taxonID	type	description	language	source
039D3B4F813C1249FF3AD88CF682F814.taxon	materials_examined	Type species: Prionospio steenstrupi Malmgren, 1867	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F813F124CFF3ADF82F54FFCF7.taxon	materials_examined	Material examined. GULF OF MEXICO. Yucatan: Off Alacranes Island, E 15, 22 ° 26 ' N, 90 ° 27 ' W, 91.2 m, 30 October 1990, DINAMO II, holotype (CNAP-ICML, UNAM: POH- 09 - 00).	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F813F124CFF3ADF82F54FFCF7.taxon	description	Description. A large species. Holotype incomplete, 17.0 mm long with 51 chaetigers, 1.0 mm wide. Color in alcohol, opaque, white. Prostomium bottle-shaped, truncate on anterior margin, with a small medial peak (Fig. 1 A), posteriorly tapered, with a long, narrow caruncle extending to the anterior edge of chaetiger 3 without (not observed) nuchal organs on either side (Fig. 1 A). Two pairs of orange subdermal eyes, arranged in a trapezoid: first pair crescent-shaped, posterior pair with large eyespots (Fig. 1 A). Palps lost. Peristomium moderate, collar-like, surrounding the prostomium, partially fused dorsally with large rounded notopodial lamellae of chaetiger 1 (Fig. 1 B). Neuropodial postchaetal lamellae on chaetiger 1 large, rounded (Fig. 1 C), slightly shorter than the notopodial lamellae. Four pairs of long, thin branchiae present on chaetigers 2 – 5; first pair longest and thickest, extending up to chaetiger 6. Pairs 1 and 4 with long, dense digitiform pinnules on the posterior face, branchiae with smooth, long, naked distal tips (Fig. 1 D). Distribution of pinnules on these two pairs similar, pinnules numerous, distributed in the middle region, but pair 4 with longer, naked distal tips; the central stem of branchial pairs 1 and 4 pinnate, elongate. Pairs 2 and 3 apinnate, densely ciliated laterally, triangular, wider, with short sharp tips (Fig. 1 E); branchiae subequal in size and length to the notopodial lamellae and smaller than those on pair 4. Notopodial postchaetal lamellae triangular on chaetigers 2 – 5 (Fig. 1 F, G); largest on chaetigers 3 – 5 with prolonged tips directed upwards; lamellae wider and squarer with triangular tips on chaetiger 6 (Fig. 1 H), becoming elongated, square on chaetiger 8 (Fig. 1 I). Lamellae of chaetiger 13 gradually becoming smaller, rounder (Fig. 1 J, K). Notopodial lamellae of middle and posterior chaetigers small, wider, dorsally directed with subtriangular dorsal edge (Fig. 1 L). Notopodial lamellae united across dorsum, forming low dorsal folds on chaetigers 6 – 11 (Fig. 1 M). Chaetiger 3 with the ventral and dorsal edges of the notopodial and neuropodial lamellae touching. Notopodial prechaetal lamellae very large on chaetigers 2 – 7, basally fused with the notopodial postchaetal lamellae (Fig. 1 F – H), smaller on chaetigers 8 – 26 (Fig. 1 I – K) and rudimentary from chaetiger 27. Neuropodial postchaetal lamellae on chaetiger 2 – 3 large and subtriangular, ventrally pointed (Fig. 1 N, O), largest on chaetiger 2; becoming oval on chaetigers 4 – 8 (Fig. 1 P), and subsequently rounded and small on far posterior chaetigers (Fig. 1 Q). Neuropodial prechaetal lamellae large on chaetigers 3 – 11 (Fig. 1 O, P), not basally fused to postchaetal lamellae, progressively decreasing in size on subsequent chaetigers. Interparapodial pouches lacking. All capillaries thicker on anterior notopodial chaetigers, alimbate, heavily granulated, with very long capillary tips (Fig. 1 R), arranged in two rows, the anterior row shorter than posterior row; notopodial and neuropodial capillaries of chaetiger 1 with short, thin chaetae, notopodial chaetae longer. Chaetae of middle notopodia arranged in two rows, with the dorsal chaetae long and ventral chaetae short, without granulations (Fig. 1 T); posterior notopodia with thinner, shorter chaetae than middle notopodia. Anterior neuropodial capillaries slender, heavily granulated, alimbate, with very long capillary tips (Fig. 1 S). Chaetae of middle neuropodial capillaries slender, not granulated, with long capillary tips (Fig. 1 U); posterior neuropodial capillaries with thinner, shorter chaetae than those on the middle neuropodia. Sabre chaetae in neuropodia from chaetiger 10, up to two per fascicle, stout, long, with slightly curved tips, distinctly granulated, without sheaths (Fig. 1 V). Neuropodial hooded hooks (Fig. 1 W) from chaetiger 16, up to 10 per fascicle, accompanied by up to three capillaries. Notopodial hooded hooks (Fig. 1 X) from chaetiger 46, up to four per fascicle, accompanied by up to three capillaries; all hooks with four pairs of small teeth above long main tooth, without secondary hood (Fig. 1 W, X); hooks with a slightly curved main tooth, neuropodial hooks with a thicker tooth and a very large principal hood (Fig. 1 W); notopodial hooks with very large stems (Fig. 1 X). Pygidium not known.	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F813F124CFF3ADF82F54FFCF7.taxon	discussion	Remarks. From the descriptions of the 35 previously known species in the P. s t e en s t r up i group (Sigvaldadóttir & Mackie, 1993: Table 2; Blake, 1996; Sigvaldadóttir 1997; Zhou & Li 2009), Prionospio austella is very similar to P. steenstrupi in having a bottle-shaped prostomium that is truncate on the anterior margin; large, subtriangular neuropodial lamellae on chaetiger 2 and ventrally pointed, low dorsal folds on the postbranchial chaetigers. However, P. austella can be distinguished from the redescription of P. steenstrupi by Sigvaldadóttir & Mackie (1993) in that the former has a prostomium with a small medial peak on the anterior margin; wider and more rounded notopodial lamellae with triangular tips on chaetiger 6, becoming square on chaetiger 8; dorsally directed notopodial lamellae with subtriangular dorsal edges on the middle and posterior chaetigers; low dorsal folds limited to chaetigers 6 – 11; large, rounded neuropodial postchaetal lamellae on chaetiger 1; large, subtriangular neuropodial lamellae on chaetiger 3; ventrally pointed, not ventrally open, pockets on the anterior chaetigers; all hooks with 4 pairs of small teeth above the long, main tooth and no secondary hood. P. austella is also very similar to P. oligopinnulata sp. nov. in having large, subtriangular ventrally pointed lamellae on chaetigers 2 and 3 and dorsal folds on the postbranchial chaetiger. However, P. austella differs from P. oligopinnulata in having a bottleshaped prostomium that is truncate on the anterior margin with a small medial peak; a long, narrow caruncle extending to the anterior edge of chaetiger 3; branchial pairs 1 and 4 with long, dense digitiform pinnules on the posterior face; low dorsal folds limited to chaetigers 6 – 11; the ventral and dorsal edges of the notopodial and neuropodial lamellae touching on chaetiger 3; very large notopodial prechaetal lamellae on chaetigers 2 – 7, basally fused with the notopodial postchaetal lamellae; large neuropodial prechaetal lamellae on chaetigers 5 – 11; neuropodial hooded hooks from chaetiger 16; notopodial hooded hooks from chaetiger 46 and all hooks without a secondary hood. Further differences between this new species from the other species examined are provided in the key and Table 1.	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F813F124CFF3ADF82F54FFCF7.taxon	materials_examined	Type locality. Southern from Mexico Gulf: Campeche.	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F813F124CFF3ADF82F54FFCF7.taxon	etymology	Etymology. The specific name is from the Latin austellus meaning south and refers to the southern region of the Gulf of Mexico.	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F8139124FFF3ADC72F500F997.taxon	materials_examined	Material examined. GULF OF MEXICO. Veracruz: Off the coast of Coatzacoalcos, E 11, 18 º 44 ' N 94 º 41.9 ' W; 173 m, muddy, 8 August 1984, coll. E. Donath Hernández, holotype (LACM-AHF-POLY 6597); Tabasco: Off the coast of Paraiso, E 7, 18 º 30 ' N, 93 º 36 ' W, IMCA II, 29 m, 27.2 ºC, 36.1 ‰, org. carb. 0.120 %, muddy-sand, 1 paratype (CNAP-ICML, UNAM: POP- 09 - 002); Campeche: Off Cayo Arcas, E 51, 19 º 59 ' N, 92 º 11 ' W, IMCA II, 188 m, 16.3 ºC, 36.2 ‰, muddy, 24 September 1988, 2 paratypes (CNAP-ICML, UNAM: POP- 09 - 002); off Cayo Arcas, E 51, 19 º 59 ' N, 92 º 11 ' W, 188 m, 16.3 ºC, 36.2 ‰, muddy, 24 September 1988, 1 paratype (CNAP-ICML, UNAM: POP- 09 - 002).	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F8139124FFF3ADC72F500F997.taxon	description	Description. Holotype incomplete, 9.0 mm long; consists of one fragment with 30 chaetigers, 1.2 mm wide. Paratypes incomplete 6.6 – 9.1 mm long, with 28 – 34 chaetigers, 1.2 – 1.3 mm wide. Color in alcohol pale white. Prostomium bottle-shaped, truncate on anterior margin (Fig. 2 A, 3 A), posteriorly tapered, with short, narrow caruncle extending to the anterior edge of chaetiger 2 (Fig. 2 A, 3 A) with large triangular nuchal organs on either side (Fig. 2 A, 3 A). Eyes absent (Fig. 3 A). One paratype with two pairs of subdermal brown eyes arranged in a trapezoid; anterior pair crescent-shaped; posterior pair small, rounded. Palps lost, except in one specimen with a pair of palps inserted anterior to the nuchal organs: the left palp in the process of regeneration and the right palp fragmented and in bad condition, with a short basal sheath (Fig. 2 A – C). Peristomium long, collar-like, surrounding the prostomium, laterally separate (Fig. 2 B), partially fused dorsally with very large rounded notopodial lamellae on chaetiger 1 (Fig. 3 A). Neuropodial postchaetal lamellae of chaetiger 1 very large and rounded (Fig. 2 B), smaller than notopodial lamellae. Four pairs of short branchiae present on chaetigers 2 – 5, the first pair longest and thickest (Fig. 3 A); sometimes the first and fourth pairs equal in length. First pair with long, dense digitiform pinnules on the lateral and posterior faces, and with short naked, smooth distal tips; distribution of the pinnules basally to distally: all pinnules arranged in curved rows (Fig. 3 B, C), in the basal and middle regions with up to 7 pinnules per row (Fig. 3 C) and in the distal region with 3 pinnules per row; the central stem of branchial pair 1 pinnate, cylindrical, very thick and with a blunt tip (Fig. 3 A). Pairs 2 – 4 apinnate; pairs 2 and 3 triangular, broad (Fig. 2 A, 3 A), densely ciliated laterally, with short, sharp tips; subequal in length to the notopodial lamellae, shorter than pinnate pair. Pair 4 cirriform (Fig. 2 A), basally united by a short, low dorsal fold; subequal or longer than notopodial lamellae. Notopodial postchaetal lamellae triangular with triangular tips widest on chaetigers 2 – 6 (Fig. 2 A); largest on chaetigers 3 – 5; lamellae of chaetigers 7 – 10 subtriangular (Fig. 2 C). Lamellae gradually becoming smaller, rounder and more dorsally directed from chaetigers 15 – 16 (Fig. 2 C, D); lamellae of posterior chaetigers rounded (Fig. 3 D). Notopodial postchaetal lamellae united, forming low dorsal crests from chaetigers 5 – 6 (Fig. 2 A, 3 A), and continuing as very low folds up to about chaetiger 23 – 31 (Fig. 2 C, D). Ventral and dorsal edges of notopodial and neuropodial lamellae not touching on anterior chaetigers (Fig. 2 D). Notopodial prechaetal lamellae moderately sized in the branchial region, not fused basally with the notopodial postchaetal lamellae, posterior chaetigers rudimentary. Anterior neuropodial postchaetal lamellae large, rectangular with rounded edges (Fig. 2 B); more angular and dorsally directed on chaetigers 3 – 4 (Fig. 3 E); rectangular, slightly more slender and ventrally directed on chaetigers 5 – 6 (Fig. 3 F); subsequent neuropodial lamellae rounded (Fig. 2 D, E, 3 G, H,) and small on far posterior chaetigers. Neuropodial prechaetal lamellae small in branchial region (Fig. 2 B), rudimentary throughout. Interparapodial pouches on chaetigers 4 – 20 / 21 non-reticulated (Fig. 2 D, E). All capillaries on anterior chaetigers alimbate, thin, granulated (Fig. 3 I, J); notopodial and neuropodial capillaries of chaetiger 1 arranged in two rows, with short, thin chaetae; notopodial chaetae longer (Fig. 3 I). Notopodial capillaries of chaetigers 2 – 11 arranged in three rows, anterior row shorter than posterior rows; middle notopodial capillaries granulated, arranged in two rows of chaetae, dorsal chaetae very long and acute (Fig. 3 I), ventral chaetae very short and acute; neuropodial capillaries in two rows, chaetae very long, acute, granulated (Fig. 3 J), first row much shorter; posterior capillaries thin and smooth. Sabre chaetae in neuropodia from chaetiger 19 – 20, up to three per parapodium (Fig. 2 F), each chaeta stout, faintly granulated distally, with slightly limbate tips, long (Fig. 3 K). Neuropodial hooded hooks (Fig. 3 L) from chaetigers 20, up to 13 per fascicle, accompanied by up to 10 capillaries; all hooks with six pairs of small teeth (Fig. 3 L) above small main tooth; hooks appear to possess very striated secondary hoods, producing a feathered effect below the main fang (Fig. 3 L); neuropodial hooks with large principal hood, ventral hooks shorter than the dorsal hooks (Fig. 2 F). Notopodial hooded hooks not observed up to chaetiger 34. Pygidium not known.	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F8139124FFF3ADC72F500F997.taxon	discussion	Remarks. Prionospio crassumbranchiata sp. nov. is closely related to P. ehlersi Fauvel, 1928 and P. saccifera Mackie & Hartley, 1990 in that it has the same shaped prostomium, branchial arrangement, presence of interparapodial pouches and structure of hooded hooks. However, Prionospio crassumbranchiata sp. nov. can be distinguished from the original description of P. ehlersi Fauvel, 1928, and the redescription of P. ehlersi by Mackie & Hartley (1990) and P. saccifera in that in P. crassumbranchiata, the peristomium is laterally separate, but partially fused dorsally with the first chaetiger; the first pair of branchiae have long, dense, digitiform pinnules on their lateral and posterior faces; the neuropodial lamellae of chaetiger 2 – 5 are rectangular, more angular, and dorsally directed; the neuropodial prechaetal lamellae on the middle chaetigers are short; all the capillaries on the anterior chaetigers are alimbate; the sabre chaetae have slightly limbate tips; all hooks have six pairs of small teeth above the main tooth and the sabre chaetae start on chaetiger 20. P. crassumbranchiata differs from P. saccifera in that the notopodial lamellae of chaetiger 1 are rounded; the first branchial pair is not united basally by a short, low dorsal crest; the interparapodial pouches start on chaetigers 4; branchial pairs 2 – 3 are apinnate, triangular, shorter, with short sharp tips. Prionospio crassumbranchiata sp. nov. also differs from the redescription of P. ehlersi by Maciolek (1985) in that the former has a bottle-shaped, anteriorly truncate prostomium; no eyes; low dorsal folds; rectangular anterior neuropodial postchaetal lamellae with rounded edges, more angular and dorsally directed on chaetigers 3 – 4, rectangular, slightly more slender and ventrally directed on chaetigers 5 – 6 and interparapodial pouches from chaetiger 4. Whereas, the specimens described by Maciolek have a rectangular prostomium that is narrower in the middle region and broadly rounded anteriorly (Maciolek, 1985: 345: Fig, 7); they also have the presence of eyes; a high dorsal crest; rounded neuropodial lamellae and interparapodial pouches starting from chaetigers 2 – 5 making them different from P. crassumbranchiata sp. nov. The differences between this new species and the other species examined are provided in the key and table 1.	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F8139124FFF3ADC72F500F997.taxon	materials_examined	Type locality. South of the Gulf of Mexico: Veracruz, Tabasco and Campeche.	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F8139124FFF3ADC72F500F997.taxon	etymology	Etymology. The specific name is from the Latin crassum meaning thick and refers to the thickness of the first pairs of branchiae. Characters P. austella sp. nov. P. crassumbranchiata P. cristata Foster P. jonatani sp. nov. P. oligopinnulata sp. P. rotunda sp. nov. sp. nov. 1971; Maciolek 1985 nov. [], this paper () Measurement (mm): Anterior fragment: Anterior fragments: a. 7.1 [6, 0.3] (12.0 – a. 16 – 23, 0.2 – 0.6 a. 4.5 - 5.2, 0.2 – 0.3 a. 5.0 – 5.5, 0.2 Length, width a. 17, 1.0 a. 6.6 – 9.1, 1.2 - 1.3 14.0, 0.4 – 0.5) b. 72 – 79 b. 38 – 40 b. 45 – 49 No. of chaetigers b. 51 b. 28 – 34 b. 33 [42] (59 – 65) Prostomium Bottle-shaped, Bottle-shaped, Subtriangular, Skittle-shaped, Square-shaped, Pyriform-shaped, anteriorly trucante, anteriorly truncate anteriorly rounded anteriorly narrow, anteriorly truncate anteriorly rounded with a small medial rounded peak pairs of eyes a. Crescent-shaped Absent or a. Rounded Absent a. Cup-shaped Absence or Anterior pair b. Large eyespots a. Crescent-shaped b. Crescent-shaped b. Cup-shaped a. Rounded Posterior pair b. Rounded b. Cup-shaped Caruncle Long, narrow Short, narrow Short, blunt Short, narrow Short, blunt and Long, blunt prominent, with a middle slit along caruncle Shape of nuchal Absent (not observed) Triangular; on both (Long; on both sides Large, V-shaped; on Long and wide; on Fused over both sides organs; position sides of caruncle of caruncle) [may both sides of caruncle both sides of caruncle of caruncle respect to the caruncle extend across caruncle] Peristomium Moderate Long Short Short Short Moderate Relative length of 1> 4 1>, = 4 1>, = 4 1> 4 1>, = 4 1> 4 pinnate branchial pairs and 4 Shape of apinnate Triangular, broad Triangular, broad Cirriform Triangular, broad Triangular, narrow Cirriform branchial pairs 2 and 3 Notopodial postchaetal Rounded, large Rounded, very large Rounded, large Rounded, very large Rounded, moderate Rounded, large lamellae (chaetiger 1) Notopodial and Touching chaetiger 3 Not touching anterior (Not overlapping or Not overlapping or Not touching anterior Not overlapping or neuropodial lamellae chaetigers touching) touching chaetigers touching overlaps or touching High dorsal crests a. Absent a. 5 – 6 a. 7 – 9 a. Absent a. 7 & 8 a. 7 Low dorsal folds b. 6 – 11 b. 7 – 23 / 31 b. 10 – 11 b. Absent b. 9 – 14 b. Absent ...... continued on the next page Characters P. austella sp. nov. P. crassumbranchiata P. cristata Foster P. jonatani sp. nov. P. oligopinnulata sp. P. rotunda sp. nov. sp. nov. 1971; Maciolek 1985 nov. [], this paper () Anterior notopodial Very large on Moderate Large in branchial Moderate in branchial Low Very low prechaetal lamellae chaetigers 2 - 7 region region Anterior neuropodial a. Subtriangular, a. Rectangular, more a. Rounded [squarish] a. Square a. Subtriangular, a. Subtriangular, postchaetal lamellae ventrally pointed angular, dorsally b. Angled, trapezoid, b. Square ventrally pointed ventrally pointed Chaetiger 2 b. Subtriangular, directed dorsally directed c. Square b. Subtriangular, b. Trapezoid, slightly Chaetiger 3 ventrally pointed b. Same as above [squarish] d. Square ventrally pointed dorsally pointed Chaetiger 4 c. Oval c. Same as above c. Rounded [squarish] c. Rounded c. Rounded Chaetiger 5 d. Oval d. Same as above d. Rounded d. Rounded d. Rounded [squarish] Anterior neuropodial Large Low Moderate Very low Low Very low prechaetal lamellae Interparapodial Absent Present Absent Absent Absent Absent pouches Anterior notopodial Thicker, alimbate, Alimbate [Bilimbate] and Unilimbate, with very Slightly unilimbate Very long and very chaetae with very long unilimbate (Very long capillary tips acute, unilimbate capillary tips long and very acute, unilimbate) Anterior neuropodial Thick, alimbate, with Alimbate [Bilimbate] Unilimbate Alimbate Short and very acute, chaetae very long capillary (unilimbate, very alimbate tips long and very acute) Sabrechaetae 10 19 – 20 10 14 – 18 10 10 Neuropodial hooded a. 16 a. 20 a. 11 – 12 [10 – 13] a. 16 – 28 a. 12 – 14 a. 11 – 12 hooks b. 4 b. 6 (12 – 13) b. 4 b. 4 b. 4 Start on chaetiger c. Absent c. Very striated b. 4 c. Absent c. Conspicuous c. Conspicuous No. of pairs of c. Conspicuous accessory teeth Secondary hood Notopodial hooded a. 46? a. 21 – 37 (26 – 34) a. 35 – 77 a. 23 – 39 a. 28 – 32 hooks b. 4 b. 4 b. 4 b. 4 b. 4 Start on chaetiger c. Absent c. Conspicuous c. Absent c. Conspicuous c. Conspicuous No. of pairs of accessory teeth Secondary hood	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F81341244FF3AD84FF02AFE6A.taxon	materials_examined	Material examined. GULF OF MEXICO. Veracruz: 20 July 1982, coll. FEDH, 8 specimens (ECOSUR-P 1411); Yucatan: Celestun lagoon, 20 º 48 ’ 12.2 ’’ N, 90 º 24 ’ 7.5 ’’ W, 0.53 m, 15.6 ‰, 26 ºC, 7.9 pH, 2.1 org. carb. BOR 2, 15 February 2008, 1 specimen (ECOSUR-P 2727). CARIBBEAN SEA. Quintana Roo: E 43, APEMEX, Yalahau, 18 January 1991, 3 specimens, coll. J. Oliva Rivera and M. Esquivel Moreno (ECOSUR-P 2728); 19 February 2001, Aventuras Beach, Quintana Roo, 20 º 15 ' 31.56 " N, 87 º 23 ' 47.50 " W, sandy beach well-sorted sand, 0.3 m, 1 specimen, coll. Leslie H. Harris, Harris, LH 01 - 450 (LACM-AHF Poly 6224); Aventuras Beach, coll. F. Pleijel, 18 February 2001, 5 specimens (ECOSUR-P 1414); Punta Nizuc, Cancún, Coll. V. H. Delgado Blas, 10 February 2001, 1 specimen (ECOSUR-P 1412); Santa Cecilia, coll. SISV, 4 November 1990, 1 specimen (ECOSUR-P 1413).	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F81341244FF3AD84FF02AFE6A.taxon	description	Description. Complete specimens, 12.0 – 14.0 mm long for 59 – 65 chaetigers, 0.4 – 0.5 mm wide. Incomplete specimens, 2.5 – 3.0 mm long for 18 – 23 chaetigers, 0.3 – 0.5 mm wide. Color in alcohol opaque white. Prostomium subtriangular, rounded anteriorly (Fig. 4 A), posteriorly tapered, with short, blunt caruncle extending to the middle edge of chaetiger 2 with large nuchal organs on either side (Fig. 4 A). Two pairs of brown subdermal eyes, arranged in a trapezoid; anterior pair small, rounded; posterior pair large, crescent-shaped (Fig. 4 A) (one specimen lacking eyes). Palps lost. Peristomium short, collar-like, surrounding the prostomium, fused dorsally with large rounded notopodial lamellae of chaetiger 1. Neuropodial postchaetal lamellae of chaetiger 1 moderate, rounded (Fig. 4 E), much smaller than twice the size of the notopodial lamellae. Four pairs of long branchiae present on chaetigers 2 – 5 (Fig. 4 A); first pair longer than fourth pair. Pairs 1 and 4 with long, slender, dense digitiform pinnules (Fig. 4 A), arranged along the posterior face of the stems; branchiae with very long, naked, smooth distal tips; basal region of branchiae naked; distribution of the pinnules similar on both pairs; pinnules slender, long, blunt in middle and basal regions of the branchiae (Fig. 4 A); the central stem of branchial pairs 1 and 4 pinnate and elongate. Pairs 2 and 3 apinnate, cirriform, long, with sparse lateral ciliation and acute distal tips (Fig. 4 A); subequal in length, shorter than pinnate pairs and longer than notopodial lamellae. Notopodial postchaetal lamellae foliaceous and wider on chaetigers 2 – 6 (Fig. 4 A), slightly cupped and facing somewhat antero-laterally; largest on chaetigers 3 – 4 with acute, long tips, progressively decreasing in size, becoming rounded on chaetigers 7 – 10 (Fig. 4 B); decreasing in size in subsequent chaetigers and short on posterior chaetigers (Fig. 4 C). High dorsal crests present on chaetigers 7 – 9, slightly shorter on chaetiger 8 (Fig. 4 D), subsequent chaetigers lacking folds. Ventral and dorsal edges of notopodial and neuropodial lamellae on anterior chaetiger neither overlapping nor touching. Notopodial prechaetal lamellae fused with postchaetal lamellae; large in branchial region, short thereafter. Neuropodial postchaetal lamellae rounded throughout (Fig. 4 E, F), except the neuropodium of chaetiger 3 which is slightly angled and trapezium-shaped, dorsally directed (Fig. 4 G), larger than the other neuropodial lamellae; pairs 1 – 3 cupped and facing somewhat antero-laterally; subsequent neuropodial lamellae small on far posterior chaetigers. Prechaetal lamellae moderate (Fig. 4 E), short throughout. Interparapodial pouches lacking. All capillaries on anterior chaetigers granulated, unilimbated (Fig. 4 H, I); notopodial and neuropodial capillaries of chaetiger 1 arranged in one row, with short, slender chaetae; notopodial chaetae longer. Notopodial capillaries of chaetigers 2 – 13 arranged in two rows, very long and very acute (Fig. 4 H), upper chaetae much longer than lower ones, chaetae curving outwards and upwards, becoming shorter later. Neuropodial capillaries of chaetigers 2 – 10 arranged in two rows, capillaries very long and very acute (Fig. 4 I) with the anterior row shorter than the posterior row, later becoming one row. Notopodial and neuropodial capillaries of middle and posterior chaetigers alimbate and without granulations. Sabre chaetae in neuropodia from chaetiger 10, up to two per fascicle, stout, curved, moderately granulated, without sheaths (Fig. 4 J). Neuropodial hooded hooks (Fig. 4 K) from chaetigers 12 – 13, up to seven per fascicle, accompanied by capillaries. Notopodial hooded hooks (Fig. 4 L) from chaetigers 26 – 34, up to five per fascicle, accompanied by up to two capillaries. All hooks with four pairs of teeth above main tooth, with short secondary hoods (Fig. 4 K, L). Pygidium with one long median cirrus and two longer lateral lobes.	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F81341244FF3AD84FF02AFE6A.taxon	discussion	Remarks. The above description agrees closely with the original description given by Foster (1971), however there are a few differences, in that in Foster’s (1971) description the prostomium is subtriangular or wedge-shaped with the anterior border blunt to slightly rounded; all capillaries on the anterior chaetigers are bilimbated; the posterior capillaries are unilimbated and the sabre chaetae are sheathed. Whereas, in the specimens in this study, the prostomium is subtriangular and very rounded anteriorly; all the capillaries are unilimbated and the sabre chaetae lack sheaths. There are also a few differences between the specimens examined in this study and the description given by Johnson (1984) in that in the latter the sabre chaetae are sheathed, whereas in this study the sabre chaetae lacked sheaths. There are a few further differences with the description of this species given by Maciolek (1985) in that Maciolek described the prostomium as having horseshoe-shaped nuchal organs with the anteriormost ends fused over the caruncle, and the sabre chaetae as having sheaths, whereas in this study the specimens have a prostomium with nuchal organs either side of the caruncle and fused above it, and the sabre chaetae lack sheaths. Another discrepancy lies in where the neuropodial and notopodial hooded hooks appear. According to Foster (1971), the neuropodial and notopodial hooks should be present from chaetigers 11 – 12 and 21 – 37, whereas Johnson (1984) states that they begin on chaetigers 10 – 12 and 26 – 30, and Maciolek (1985) 10 – 13 and 21 – 37. In contrast, the material examined here had neuropodial hooks from chaetigers 12 – 13 and notopodial hooded hooks from chaetigers 26 – 34; this could, however, be due to the size of the specimens. The differences between P. cristata and the other species examined are provided in the key and Table 1. Geographical distribution. North Atlantic; Delaware, North Carolina, Florida; Gulf of México: Port Aransas, Texas, Veracruz, Yucatán, Caribbean Sea: Quintana Roo, Puerto Rico, Curaçao.	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F81311247FF3ADEC9F047F996.taxon	materials_examined	Type material. GULF OF MEXICO. Tabasco: Off the coast of La Venta, E 16, 18 º 39.8 ' N, 94 º 13.1 ' W, 147 m, muddy bottom, holotype (LACM-AHF-POLY 6598), coll. E. Donath Hernández, 10 August 1984; off the coast of La Venta, E 12, 18 º 31 ' N, 94 º 36 ' W, 63 m, 1 paratype (LACM-AHF-POLY 6599), coll. E. Donath Hernández, 10 August 1984; off Paraíso, E 20, 18 º 32.1 ' N, 93 º 43.2 ' W, 38 m; sand, 3 paratypes (LACM-AHF-POLY 6600); Veracruz: between Alvarado and Punta Roca Partida, E 7, 18 º 51 ' N, 95 º 41 ' W, 48 m, muddy, 1 paratype ECOSUR 0167, coll. E. Donath Hernández, August 1984; off the coast of Coatzacoalcos, E 12, 18 º 31 ' N, 94 º 36 ' W, 63 m, 1 paratype ECOSUR 0168 August 1984; Yucatan: off Alacranes Island, 5 March 2002, E 5, 22 º 21 ’ 140 ’’ N, 89 º 44 ’ 970 ’’ W, 1 paratype ECOSUR 0169. Non-type material. GULF OF MEXICO. Campeche: Off Cayo Arcas, E 51, 19 º 59 ' N, 92 º 11 ' W, IMCA II, 188 m, 16.34 ºC, 36.150 ‰, muddy, 1 specimen (CNAP-ICML, UNAM: PO- 09 - 062), 24 September 1988; in front of Frontera, E 76, 19 º 15 ' N, 92 º 28 ' W, IMCA II, 73 m, muddy, 22.91 ºC, 36.440 ‰, 1.150 % organic matter, 1 specimen (CNAP-ICML, UNAM: PO- 09 - 062), 27 September 1988; E 51, 19 º 45 ' N, 91 º 28 ' W, Dinamo II, 33 m, 27.8 ºC, 36.49 ‰, muddy, 1 specimen (CNAP-ICML, UNAM: PO- 09 - 062), 30 November 1990; between Cayo Arcas and Frontera, E 65, 19 º 43 ' N, 92 º 10 ' W, 99 m, 22 ºC, 36.46 ‰, muddy, 1 specimen (CNAP-ICML, UNAM: PO- 09 - 062), 3 November 1990; E 43, IMCA IV, 2 specimens (CNAP-ICML, UNAM: PO- 09 - 062), 3 October 1989; IMCA II, (CNAP-ICML, UNAM: PO- 09 - 062), 24 September 1988.	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F81311247FF3ADEC9F047F996.taxon	description	Description. Holotype incomplete, 12 mm long for 44 chaetigers, 0.8 mm wide. Complete paratypes: 16 – 23 mm long for 72 – 79 chaetigers, 0.2 – 0.6 mm wide. Incomplete paratypes: 5 – 9 mm long for 27 – 44 chaetigers, 0.4 – 0.6 mm wide. Color in alcohol opaque white, one specimen brown. Some specimens reproductive, with oocytes present on chaetigers 24 – 67. Prostomium anteriorly narrow, widening and becoming rounded in midregion (Fig. 5 A), posteriorly tapered, with short, narrow caruncle extending to the anterior edge of chaetiger 2 and with large V-shaped nuchal organs on either side (Fig. 5 A). Eyes absent. Palps lost. Peristomium short (Fig. 6 A), collar-like, surrounding prostomium, fused dorsally with very large, rounded notopodial lamellae on chaetiger 1 (Fig. 5 A, 6 A). Neuropodial postchaetal lamellae of chaetiger 1 small, rounded (Fig. 5 B, 6 A), much smaller than 1 / 3 of the size of the notopodial lamellae. Four pairs of short branchiae present on chaetigers 2 – 5 (Fig. 5 C); first pair longest and thickest, always up to 5 times longer than the fourth pair (Fig. 5 C, 6 A); first pair extending up to chaetiger 6; fourth pair longer than notopodial lamellae (Fig. 5 C, 6 A). Pairs 1 and 4 with long, dense digitiform pinnules, the first pair with pinnules arranged along the outer lateral margin and the fourth pair with pinnules on the posterior face (Fig. 5 C); pair 4 with fewer pinnules, branchiae with long, naked, smooth distal tips (Fig. 5 B, C); central stem of branchial pairs 1 and 4 pinnate, elongate; pair 1 multi-segmented, pair 4 smoother (less segmented) and slightly ciliated laterally (Fig. 5 B, C). Pairs 2 and 3 apinnate, triangular, wide, with short tapered tips, densely ciliated laterally (Fig. 5 B, C), subequal in length, slightly smaller or larger than notopodial lamellae. Notopodial postchaetal lamellae of chaetigers 2 – 4 triangular, slender with wide, rounded bases (Fig. 5 B, 6 B), largest on chaetigers 3 – 5 with sharp tips; lamellae on chaetigers 6 – 14 subtriangular with blunt tips (Fig. 5 B, C, 6 C). Subsequent notopodial lamellae rounded (Fig. 5 D, 6 D), small on far posterior chaetigers (Fig. 6 E). Ventral and dorsal edges of notopodial and neuropodial lamellae not touching on chaetigers 2 – 4 (Fig. 5 B, 6 A). Notopodial prechaetal lamellae moderate in branchial region, slightly basally fused with notopodial postchaetal lamellae (Fig. 6 B), prechaetal lamellae of chaetiger 9 and subsequent lamellae progressively decreasing in size, split and becoming rounder and smaller (Fig. 5 D, 6 C, D), short on far posterior chaetigers (Fig. 6 E). Dorsal folds or crests absent (Fig. 5 C). Neuropodial postchaetal lamellae on chaetiger 2 – 7 square, largest on chaetigers 3 – 4 (Fig. 5 B); subsequent neuropodial lamellae rounded (Fig. 5 B, D, 6 C, D), smallest on far posterior chaetigers (Fig. 6 E). Neuropodial prechaetal lamellae very small in branchial region (Fig. 5 B, 6 D, E), rudimentary throughout. Interparapodial pouches lacking. All capillaries on anterior chaetigers unilimbate, heavily granulated and with long capillary tips (Fig. 6 F, G); notopodial capillaries of chaetiger 1 arranged in a tuft and neuropodial capillaries of chaetiger 1 arranged in one row, with short, thin chaetae, notopodial chaetae longer (Fig. 6 F). Notopodial capillaries from chaetiger 2 onwards arranged in three rows, anterior row shorter than posterior rows; chaetae on middle notopodia arranged in two rows (Fig. 5 D), dorsal chaetae longer than ventral chaetae; thin, smooth chaetae on posterior notopodia arranged in one row. Neuropodial capillaries similar to notopodial capillaries, but shorter and slenderer (Fig. 6 G), arranged in two rows (Fig. 5 D) from chaetiger 2 up to chaetiger 16; chaetae on posterior neuropodia arranged in one row. Sabre chaetae in neuropodia from chaetigers 14 – 18 (holotype 18), one or two per parapodium, robust, long, moderately granulated, without sheaths (Fig. 6 H). Neuropodial hooded hooks (Fig. 5 E) from chaetigers 16 – 28 (holotype 21), up to eight per fascicle, alternating with long, thin capillaries; posterior hooks accompanied by up to three slender, smooth capillaries. Notopodial hooded hooks (Fig. 6 I) from chaetigers 35 – 57, up to four per fascicle, alternating with thin capillaries (Fig. 5 F); all hooks with four pairs of small teeth above main tooth (Fig. 5 E, 6 I) and without secondary hoods (Fig. 6 I). Neuropodial and notopodial hooks with a large main hood (Fig. 5 E, F, 6 I). The central stem of the hook curved, broken in cross-section, showing the internal nature (Fig. 5 E). Pygidium with one long median cirrus and two short lateral lobes (Fig. 6 J).	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F81311247FF3ADEC9F047F996.taxon	discussion	Remarks. Prionospio jonatani sp. nov. is very similar to P. dubia Day, 1961 in that both species have the same shaped prostomium, branchiae of the same length, the same shaped anterior notopodial and neuropodial lamellae, granulated anterior chaetae capillaries and hooded hooks without secondary hoods. Prionospio jonatani can be distinguished from the original description of P. dubia Day, 1961 and the descriptions of P. dubia given by Wilson (1990) and Sigvaldadóttir and Mackie (1993), in that the former has a narrower prostomium in the anterior region, the first notopodial lamellae are larger, the notopodial lamellae on chaetigers 6 – 21 are subtriangular, the notopodial prechaetal lamellae are slightly basally fused with the notopodial postchaetal lamellae in the branchial region, the neuropodial postchaetal lamellae on chaetiger 3 are square, all the capillaries are unilimbate on the anterior chaetae, the sabre chaetae are robust and moderately granulated, and all hooded hooks have four pairs of small teeth above the main tooth. The specimens of Prionospio jonatani examined here also differ from the description given by Maciolek (1985) in that the former have a narrower prostomium in the anterior region, the eyes are absent, the first notopodial lamellae are larger, the neuropodial postchaetal lamellae of chaetiger 1 are rounded, the capillaries of the posterior chaetigers are not striated nor slightly granulated, and neither these capilliaries nor the sabre chaetae have sheaths. Wilson suggested that Maciolek (1985) may have lumped more than one species together in her description of P. dubia, especially given the widespread localities reported for this species (ranging from the Atlantic coast of North America, Surinam, the Mediterranean, the Canary Islands and the Bay of Biscay, Sweden, South Africa) and the depths at which it has been collected (85 – 2379 m). This is maybe why Maciolek’s (1985) description differs from that of the material from South Africa examined by Wilson (1990), notably in the positions at which the neuropodial sabre chaetae and hooded hooks appear, the shape of the prostomium and the length of the first pair of branchiae. Due to this, and the fact that the P. dubia specimens examined by Maciolek (1985), are widely distributed, Wilson (1990) proposed that the records of this species be verified. The differences between this new species from the other species examined in this study are provided in the key and Table 1.	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F81311247FF3ADEC9F047F996.taxon	etymology	Etymology. This species is dedicated to the memory of my beloved son Jonatán Iván Delgado Martinez (1993 – 2014) who left us too soon and so suddenly. My son, Jonatán, was a very cheerful, enthusiastic, passionate, friendly person; a tireless reader, poet, writer, composer, musician and rock drummer. You will always be in our hearts and we miss you immensely my beloved Jona.	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F81311247FF3ADEC9F047F996.taxon	materials_examined	Type locality. Southern Gulf of Mexico: Veracruz, Tabasco, Campeche and Yucatán.	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F8132125AFF3AD9A8F73EFE4E.taxon	materials_examined	Type material. GULF OF MEXICO. Campeche: Off Campeche, E 46, 20 º 14 ' N, 91 º 05 ' W, Dinamo I, 17 m, 27 ºC, 36.8 ‰, sand, 2 February 1990, holotype (CNAP-ICML, UNAM: POH- 09 - 002); off Campeche, E 46, 20 º 14 ' N, 91 º 05 ' W, Dinamo I, 17 m, 27 ºC, 36.8 ‰, sand, 2 February 1990, 2 paratypes (CNAP-ICML, UNAM: POP- 09 - 003). Non-type material. GULF OF MEXICO. Yucatan: Off Celestún, E 30, 21 º 02 ' N, 91 º 05 ' W, Dinamo II, 31 m, 27.5 ºC, 36.8 ‰, sand, 30 October 1990, 2 specimens (CNAP-ICML, UNAM: PO- 09 - 063).	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F8132125AFF3AD9A8F73EFE4E.taxon	description	Description. Holotype incomplete, 5.0 mm long for 38 chaetigers, 0.3 mm wide. Paratypes complete, 4.5 – 5.2 mm long for 38 – 40 chaetigers, 0.2 – 0.25 mm wide. Color in alcohol pale white. Prostomium square-shaped, truncate anteriorly (Fig. 7 A), posteriorly tapered with short, blunt, prominent caruncle, middle slit along caruncle (Fig. 7 A, C); caruncle extending to the anterior edge of chaetiger 2, longer than prostomium (Fig. 7 A), with long, wide, ciliate nuchal organs (Fig. 7 B, C) on either side (Fig. 7 A, C). Two pairs of red-brown subdermal eyes, both pairs cup-shaped (Fig. 7 A), arranged in a trapezoid; anterior pair small, posterior pair large and elongated (Fig. 7 A) (holotype without eyes). Palps lost. Peristomium short (Fig. 7 A – C), collar-like, surrounding prostomium, fused dorsally with moderately rounded notopodial lamellae on chaetiger 1 (Fig. 7 A, C). Neuropodial postchaetal lamellae of chaetiger 1 moderate, rounded (Fig. 7 A), much smaller than twice the size of the notopodial lamellae. Four pairs of long branchiae present on chaetigers 2 – 5 (Fig. 7 B, C). First and fourth pairs longest (Fig. 7 B, C), generally first pair longer: up to 5 times the size of the fourth pair, but pairs 1 and 4 sometimes equal in length; pairs 1 and 4 with a few short, digitiform pinnules on the lateral face, branchiae with long naked, smooth distal tips (Fig. 7 B, C). Distribution of pinnules on these two pairs similar, pinnules few, sparsely distributed in the middle of the branchiae (Fig. 7 B, C); central stems of pairs 1 and 4 of the branchiae pinnate, elongate, pair 1 slightly ciliated laterally (Fig. 7 B). Pairs 2 and 3 apinnate, triangular, narrow, with dense lateral ciliation and sharp tips (Fig. 7 B, C); subequal in length, shorter than the pinnate pairs, but longer than the notopodial lamellae (Fig. 7 B, C). Notopodial postchaetal lamellae triangular, slender on chaetigers 2 – 6, with wide bases, thin from half way up and elongated (Fig. 7 B, D, E), largest on chaetigers 3 – 4; lamellae of chaetiger 7 subtriangular with blunt tips (Fig. 7 B, F), progressively decreasing in size and becoming rounded on chaetigers 9 – 10 (Fig. 7 G). Notopodial lamellae united across dorsum, forming high dorsal crests (Fig. 7 J) on chaetigers 7 – 8 (one specimen with a low fold on chaetiger 8) (Fig. 7 B), and low dorsal folds on chaetigers 9 – 14 (Fig. 7 B, J); lamellae on posterior chaetigers small, rounded (Fig. 7 H, I). Ventral and dorsal edges of notopodial and neuropodial lamellae not touching on anterior chaetigers (Fig. 7 C, D). Notopodial prechaetal lamellae low in branchial region, not basally fused with notopodial postchaetal lamellae (Fig. 7 A, D, E), becoming rounder and smaller on far posterior chaetigers (Fig. 7 I). Neuropodial postchaetal lamellae on chaetigers 2 – 3 large, subtriangular, ventrally pointed (Fig. 7 C, D), becoming rounded on chaetigers 4 – 5 (Fig. 7 D, E); gradually decreasing in size on following chaetigers (Fig. 7 F – H), smallest on far posterior chaetigers (Fig. 7 I). Neuropodial prechaetal lamellae rounded, small in anterior region (Fig. 7 D – F), rudimentary throughout. Interparapodial pouches lacking. Anterior chaetae all heavily granulated and with very long capillary tips (Fig. 7 K, L); notopodial chaetae slightly unilimbate (Fig. 7 K), neuropodial chaetae alimbate (Fig. 7 L); notopodial and neuropodial capillaries arranged in two rows from chaetiger 1 onwards, with short, thin chaetae, notopodial chaetae longer with the posterior row longest; chaetae from chaetiger 18 arranged in one row, chaetae thin, without granulations and with very long capillary tips (Fig. 7 M). Neuropodia from about chaetiger 10 also arranged in one row, chaetae thin, without granulations and with very long capillary tips (Fig. 7 N); dorsal chaetae long and ventral chaetae short; posterior notopodia with thinner and shorter chaetae than middle notopodia. Sabre chaetae in neuropodia from chaetiger 10, one per fascicle, moderately granulated and without sheaths (Fig. 7 O). Neuropodial hooded hooks (Fig. 7 P) from chaetigers 12 – 14 (holotype: 12), up to seven per fascicle, alternating with thin capillaries, posterior hooks accompanied by up to two capillaries. Notopodial hooded hooks from chaetigers 23 – 39 (holotype: 30) (Fig. 7 Q) equal in length to neuropodial hooks, but slenderer and fewer per fascicle; up to four per fascicle, accompanied by up to four thin capillaries; all hooks with four pairs of small teeth above main tooth and conspicuous secondary hood (Fig. 7 P, Q). Pygidium with one long, thin median cirrus and two short lateral lobes (Fig. 7 R).	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F8132125AFF3AD9A8F73EFE4E.taxon	discussion	Remarks. Examination of the other species in the steenstrupi - group (Sigvaldadóttir & Mackie, 1993: Table 2; Blake, 1996; Sigvaldadóttir 1997; Zhou & Li 2009) shows that Prionospio oligopinnulata nov. sp. is most similar to P. depauperata Imajima 1990 and P. kulin Wilson 1990 as all three species have subtriangular, ventrally pointed neuropodial postchaetal lamellae on chaetigers 2 – 3 and dorsal crests on several chaetigers. However, P. oligopinnulata differs from P. depauperata in that in the former the prostomium is truncated anteriorly, the notopodial and neuropodial lamellae on chaetiger 1 and on the posterior parapodia are rounded, low dorsal folds are present from chaetigers 9 – 14, the anterior notopodial chaetae are slightly unilimbate and the neuropodial chaetae alimbate, the sabre chaetae lack sheaths, neuropodial hooded hooks are present from chaetigers 12 – 14 and notopodial hooded hooks from chaetigers 23 – 33, and all hooks have four pairs of small teeth above the main tooth. Prionospio oligopinnulata differs from P. kulin in that the former has a long, blunt, prominent caruncle, well developed parapodial lamellae on chaetiger 1, rounded posterior neuropodial lamellae, low dorsal folds on chaetigers 9 – 14, an absence of interparapodial pouches, and hooks with four pairs of small teeth above the main tooth all with a secondary hood. Prionospio oligopinnulata also differs from P. k ul i n and P. depauperata in that it has a slit along the middle of the caruncle. The differences between this new species and the other species examined are provided in the key and Table 1.	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F8132125AFF3AD9A8F73EFE4E.taxon	etymology	Etymology. The specific name is from the Greek oligo meaning few and refers to the few pinnules distributed scarcely on the branchiae.	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F8132125AFF3AD9A8F73EFE4E.taxon	materials_examined	Type locality. Gulf of Mexico Campeche, Yucatán.	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F812F125CFF3ADEE0F783FBF1.taxon	materials_examined	Material examined. CARIBBEAN SEA. Quintana Roo: Mahahual 24 October 2008, coll. V. H. Delgado-Blas, holotype (LACM-AHF-POLY 6601); E 31, on the coast at Yalahau, 22 º 30 ’ 990 ’’ N, 087 º 05 ’ 010 ’’ W, November 2001, 2 paratypes (ECOSUR 0170); GULF OF MEXICO. Yucatan: E 5, on the coast at Progreso, 22 º 47 ’ 035 ’’ N, 90 º 20 ’ 15 ’’ W, October 2001, 1 paratype (LACM-AHF-POLY 6602).	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F812F125CFF3ADEE0F783FBF1.taxon	description	Description. Holotype complete, 5.0 mm long for 49 chaetigers, 0.2 mm wide. Paratypes complete, 45 – 47 chaetigers, 5.5 mm long, 0.2 mm wide. Color in alcohol pale white. Prostomium pyriform-shaped, rounded anteriorly (Fig. 8 A), tapered posteriorly, with long, blunt caruncle extending to the posterior edge of chaetiger 2 with nuchal organs fused on either side (Fig. 8 A). Specimens with two pairs of red-brown subdermal eyes or eyes absent (1 paratype); anterior pair small, rounded (Fig. 8 B); posterior pair cup-shaped. Palps lost (Holotype), except one specimen with a pair of long palps, grooved, lacking basal sheaths (Fig. 8 C) extending up to chaetiger 12. Peristomium moderate in size, collar-like, surrounding the prostomium, fused dorsally with large, rounded notopodial lamellae of chaetiger 1 (Fig. 8 A, B, D). Neuropodial postchaetal lamellae of chaetiger 1 large, rounded (Fig. 8 B, D), much smaller than half the size of the notopodial lamellae. Four pairs of long branchiae present on chaetigers 2 – 5 (Fig. 8 B); first pair longer than fourth pair. Pairs 1 and 4 with a few long, digitiform pinnules on posterior face, branchiae with very long naked, smooth distal tips (Fig. 8 A – B) and naked basal region; pinnules thick, blunt, long on middle region of the branchiae (Fig. 8 A); the central stem of branchial pairs 1 and 4 pinnate, elongate. Pairs 2 and 3 apinnate, cirriform, long with a dense lateral ciliation (Fig. 8 B); subequal in length, shorter than pinnate pairs, but longer than notopodial lamellae. Notopodial postchaetal lamellae triangular and thinner on chaetigers 2 – 5 (Fig. 8 D); lamellae larger on chaetiger 4, largest on chaetigers 3 – 4 and with triangular tips (Fig. 8 D); becoming more oval on chaetigers 7 – 14 (Fig. 8 E); progressively decreasing in size on middle chaetigers (Fig. 8 F) and becoming more rounded on posterior chaetigers (Fig. 8 G). Notopodial lamellae united across dorsum of chaetiger 7 only, forming a high dorsal crest (Fig. 8 H); chaetiger 8 and subsequent chaetigers without dorsal fold. Ventral and dorsal edges of notopodial and neuropodial lamellae not touching on anterior chaetiger (Fig. 8 B, D). Notopodial prechaetal lamellae very short in branchial region (Fig. 8 B, D), inconspicuous thereafter. Anterior neuropodial postchaetal lamellae rounded throughout, except the neuropodia on chaetigers 2 – 3; neuropodium on chaetiger 2 large and subtriangular, ventrally pointed (Fig. 8 D), neuropodium on chaetiger 3 trapezoid, slightly dorsally pointed (Fig. 8 D); second and third pairs larger than the other neuropodial lamellae; subsequent neuropodial lamellae small and rounded on middle chaetigers (Fig. 8 D – F) and subtriangular on posterior chaetigers (Fig. 8 G). Neuropodial prechaetal lamellae very short (Fig. 8 D), rudimentary throughout. Interparapodial pouches lacking. All capillaries on the anterior chaetigers granulated (Fig. 8 I, J); notopodial and neuropodial capillaries of chaetiger 1 arranged in one row, with short, slender chaetae; notopodial chaetae longer. Notopodial capillaries of chaetigers 2 – 12 arranged in two rows, with very long and very acute unilimbated chaetae (Fig. 8 I); upper chaetae much longer than lower ones, chaetae curving outwards and upwards, in posterior segments becoming shorter. Neuropodial capillaries of chaetigers 2 – 9 arranged in two rows, with short and very acute alimbated chaetae (Fig. 8 J), anterior row shorter than posterior row, later becoming one row; longer, slender and non-granulated capillaries on median and posterior chaetigers. Sabre chaetae in neuropodia from chaetiger 10, up to two per fascicle, stout, curved, moderately granulated, without sheaths (Fig. 8 K). Neuropodial hooded hooks (Fig. 8 L) from chaetigers 11 – 12, up to six per fascicle, accompanied by capillaries. Notopodial hooded hooks (Fig. 8 M) from chaetigers 28 – 32, up to four per fascicle. Accompanied by up to two thin capillaries. All hooks with four pairs of teeth above the main tooth, with large secondary hoods (Fig. 8 L, M). Pygidium with one long median cirrus and two longer lateral lobes (Fig. 8 N). One specimen had up to 12 gregarine parasites within the gut, between chaetigers 7 to 24 (Fig. 8 O).	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F812F125CFF3ADEE0F783FBF1.taxon	discussion	Remarks. Examination of the 35 previously known species of the P. steenstrupi group (Sigvaldadóttir & Mackie, 1993: Table 2; Blake, 1996; Sigvaldadóttir 1997; Zhou & Li 2009) reveals that Prionospio rotunda sp. nov. is very similar to P. fallax Södertröm, 1920 and P. membranacea Imajima 1990 in having a dorsal crest on chaetiger 7 and the same shaped neuropodial lamellae on chaetiger 2. However, Prionospio rotunda differs from the redescription of P. fallax by Sigvaldadóttir & Mackie (1993) and the original description of P. membranacea in that the former has an anteriorly rounded prostomium; a long, blunt caruncle extending to the posterior edge of chaetiger 2 with nuchal organs fused over either side, cirriform second and third branchial pairs; trapezoid, ventrally pointed neuropodial lamellae on chaetiger 3, subtriangular neuropodial lamellae on the posterior chaetigers, and all hooks with four pairs of teeth above the main tooth. In addition, P. ro t u nd a differs from P. fallax in that the former has branchiae with pinnules arranged along the posterior margins of the stems, and large, rounded neuropodial lamellae on chaetiger 1. Finally, P. rotunda differs from P. membranacea in that the former has neuropodial hooded hooks from chaetigers 11 – 12 and notopodial hooded hooks from chaetigers 28 – 32. The differences between P. rotunda and the other species examined are provided in the key and Table 1. Gregarine parasites were found in the digestive tract of one specimen of P. ro t u nd a sp. nov. Douglas & Jones (1991) reported on gregarine associated with eight spionid species (Boccardia proboscidea Hartman, 1940, Boccardiella hamata (Webster, 1879) (cited as Boccardia hamata), Polydora cornuta Bosc, 1802 (cited as Polydora ligni Webster, 1879), Polydora nuchalis Woodwick, 1953, Dipolydora socialis (Schmarda, 1861) (cited as Polydora socialis), Streblospio benedicti Webster, 1879, Spio maculata (Hartman, 1961) (cited as Scolelepis maculata), and Pygospio elegans Claparède, 1863) where the gregarine were found in the gut lumen.	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F812F125CFF3ADEE0F783FBF1.taxon	etymology	Etymology. The species name is from the Latin rotundus meaning rounded and refers to the anteriorly rounded prostomium.	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
039D3B4F812F125CFF3ADEE0F783FBF1.taxon	materials_examined	Type locality. Gulf of Mexico: Yucatan, Caribbean Sea: Mahahual.	en	Delgado-Blas, Víctor Hugo (2015): Prionospio (Polychaeta, Spionidae) from the Grand Caribbean Region, with the descriptions of five new species and a key to species recorded in the area. Zootaxa 3905 (1): 69-90, DOI: 10.11646/zootaxa.3905.1.4
