Scyllarinae, Latreille, 1825

Coutures, Emmanuel & Webber, Richard, 2005, Phyllosoma and nisto stages of Scyllarinae sp. D (Crustacea: Decapoda: Scyllaridae) from the south-west lagoon of New Caledonia, Zootaxa 873, pp. 1-20 : 4-16

publication ID	https://doi.org/10.11646/zootaxa.873.1.1
DOI	https://doi.org/10.5281/zenodo.15807458
persistent identifier	https://treatment.plazi.org/id/03C88787-7556-B209-746E-FAE34262FF55
treatment provided by	Felipe
scientific name	Scyllarinae
status

Treatment

A total of 182 phyllosomas and 24 nistos were caught. All nistos and 169 phyllosomas were assigned to Scyllarinae View in CoL sp. D. Measurements of the phyllosoma stages are summarised in Table 1 View TABLE 1 ; morphological features of the phyllosoma stages are summarised in Table 2 View TABLE 2 .

Description

Stage I ( Tab. 1 View TABLE 1 & 2 View TABLE 2 ; Fig. 2 a–d View FIGURE 2 ). N = 34 (specimens measured). Mean dimensions: TL 1.47 mm (SD: 0.05); AL 0.59 mm (0.04); EL 0.57 mm (0.03); CL 0.90 mm (0.03); CW 1.03 mm (0.06); TW 0.55 mm (0.02); CW/CL 0.88 (0.04).

Eyestalk unsegmented. Cephalic shield lozengeshaped. Antennule (A1) uniramous, unsegmented, terminating in three long terminal setae and a short spine at outer distal angle; a medial seta at submedian position where future inner ramus will appear. Antenna (A2) uniramous, terminating in spine, with two subterminal setae; basal antennal gland protruding beyond antennal margins. First maxilla (Mx1) biramous, basal endite with five setae, coxal endite with three setae. Second maxilla (Mx2) consisting of elongated basal article with two small spines on anterior margin, smaller apical article terminating in four plumose setae (setules not illustrated). Second maxilliped (Mxp2) of four articles, armed as illustrated. Third maxilliped (Mxp3) of four articles, lacking exopod. First pereopod (P1) and second pereopod (P2) biramous, exopod of each bearing seven pairs plumose natatory setae; third pereopod (P3) with small exopod bud; fourth pereopod (P4) visible as bud. P1–3 with subexopodal spine; Mxp3 and P1–3 with ventral coxal spine, accessory seta adjacent to each coxal spine. Abdomen almost parallelsided, terminating on each side in a budlike posterolateral process supporting a spine with three longer basal setae. Telson not differentiated in this stage.

Stage II ( Tab. 1 View TABLE 1 & 2 View TABLE 2 ; Fig. 3 a–d View FIGURE 3 ). N = 35. Mean dimensions: TL 2.20 mm (0.11); AL 0.73 mm (0.04); EL 0.87 mm (0.08); CL 1.47 mm (0.08); CW 1.55 mm (0.13); TW 0.79 mm (0.05); CW/CL 0.96 (0.06).

Eyestalk segmented with single joint at base of eye. Cephalic shield more trapezoidal than in stage I with maximum width median. A1 tip as for stage I but submedian seta beginning to differentiate into inner ramus; A2 about 1/4 length of A1, setation as in stage I; spines and setae of Mx1, Mx2, Mxp2, abdomen, as for stage I. Exopod of P1–2 with eight pairs of plumose setae; exopod of P3 still a bud but three times longer than in stage I; P4 two times longer than abdomen, unsegmented, with exopod bud. Abdomen bearing posterolateral spine, three basal setae.

Stage III ( Tab. 1 View TABLE 1 & 2 View TABLE 2 ; Fig. 4 a–d View FIGURE 4 ). N = 13. Mean dimensions: TL 3.10 mm (0.39); AL 0.99 mm (0.06); EL 1.22 mm (0.10); CL 2.28 mm (0.30); CW 2.24 mm (0.35); TW 1.11 mm (0.12); CW/CL 1.01 (0.08).

Cephalic shield subcircular with maximum width medial; A1 with inner ramous differentiated, pointed, outer ramus with 2 rows of sensory setae distally, ramus terminates in two long setae; A2 almost ½ length of A1, uniramous, unsegmented but with slight bulge medially; Mx1, Mx2 as in stage II; P3 exopod now with natatory setae, P1–3 exopod with 9 (min. = 9, max. = 11), 10 (9–10), 6 (5–6) pairs of setae respectively; P4 endopod segmented, exopod longer than in stage II but without setation, subexopodal spine present, ventral coxal spine and accessory seta present; P5 visible as bud. Uropods visible as rudimentary buds on each side of abdomen. Abdomen bearing posterolateral spine with three basal setae.

Stage IV ( Tab. 1 View TABLE 1 & 2 View TABLE 2 ; Fig. 5 a–d View FIGURE 5 ). N = 7. Mean dimensions: TL 4.14 mm (0.39); AL 1.16 mm (0.08); EL 1.54 mm (0.06); CL 2.97 mm (0.19); CW 2.94 mm (0.39); TW 1.60 mm (0.12); CW/CL 1.02 (0.09).

A1 with twosegmented peduncle, outer ramus with five rows of sensory setae (+ two terminal setae), inner ramus 1/3 length of outer; A2 1/2 length of A1, unsegmented, now biramous with small, pointed outer process; Mx1 with additional setae, Mx2 with two spines on first article but apical article and plumose terminal setae have disappeared; P4 exopod now with natatory setae, P1–4 exopods with 11 (10–12), 12 (10–12), 9 (8–9), 5 (5– 6) pairs of plumose setae respectively; P5 unsegmented, about 1/2 length of abdomen; abdomen with 4 pairs of pleopod buds; uropod bud slightly forked, protruding beyond lateral margin of abdomen. Incipient telson (section of abdomen posterior to uropod buds) retains posterolateral processes, each tipped with a spine and three setae.

Stage V ( Tab. 1 View TABLE 1 & 2 View TABLE 2 ; Fig. 6 a–d View FIGURE 6 ). N = 24. Mean dimensions: TL 4.99 mm (0.18); AL: 1.29 mm (0.03); EL 1.69 mm (0.17); CL 3.46 mm (0.11); CW 3.49 mm (0.19); TW 1.83 mm (0.25); CW/CL 0.99 (0.04).

A1 with twosegmented peduncle, outer ramus with sixseven rows of sensory setae (+ two terminal setae), inner ramus 1/2 length of outer; A2 over 1/2 length of A1, pointed outer lobe now larger than in stage IV; Mx1 similar to stage IV, Mx2 expanded anteriorly and posteriorly; first maxilliped (Mxp1) present as bud immediately posterior to Mx2; P1– 4 exopods with 12 (12–13), 12 (12–13), 10 (10–10), 7 (7–8) pairs of plumose setae respectively; P5 segmented at base, about 3/4 length of abdomen; pleopods clearly visible as uniramous buds; uropods biramous, unsegmented, shorter than telson, posterolateral spines no longer supported by posterolateral processes but retaining three basal setae. NB. some specimens were assigned to stage V because the differentiation of uropods and telson was obviously more advanced than in the previous stage while the A1 peduncle remained 2segmented.

Stage VI ( Tab. 1 View TABLE 1 & 2 View TABLE 2 ; Fig. 7 a–d View FIGURE 7 ). N = 40. Mean dimensions: TL 7.36 mm (0.55); AL: 1.62 mm (0.11); EL 2.12 mm (0.16); CL 4.90 mm (0.39); CW 5.03 mm (0.34); TW 2.62 mm (0.23); CW/CL 0.97 (0.04).

A1 now with 3segmented peduncle, outer ramus with nineten rows of sensory setae (and two terminal setae), inner ramus almost as long as outer ramus; A2 5/8 length of A1, unsegmented, unarmed but both rami longer, more robust than in previous stage; Mx1 with additional setae, Mx2 trilobed anteriorly bearing three spines, expanded posteriorly; Mxp1 larger than in previous stage, now slightly bilobed; Mxp2 and Mxp3 with rudimentary exopod buds discernable as swellings on proximal segments; P1–4 exopods with 14 (14– 15), 14 (14–15), 12 (11–12), 10 (9–10) pairs of plumose setae respectively; P5 as long as abdomen; pleopod buds biramous; uropods expanded, both rami reaching slightly beyond rounded posterior margin of telson, posterolateral spine with three basal setae remaining on posterior margin of telson.

Stage VII (Final) ( Tab. 1 View TABLE 1 & 2 View TABLE 2 ; Fig. 8 a–d View FIGURE 8 ). N = 8. Mean dimensions: TL 10.02 mm (0.98); AL: 2.11 mm (0.16); EL 2.63 mm (0.15); CL 5.83 mm (0.69); CW 5.97 mm (0.73); TW 3.13 mm (0.49); CW/CL 0.98 (0.06).

A1 inner ramus slightly outreaching outer, outer ramus with 11–12 rows of sensory setae; A2 now 7/8 length of A1, flattened, considerably expanded laterally but remaining unsegmented, unarmed; Mx1 with additional setae; Mx2 flattened and considerably expanded to anterior and posterior; Mxp1 expanded, crosiershaped; Mxp2 bearing rudimentary, elongated, unarmed exopod bud; Mxp3 with smaller exopod bud; full complement of gill buds now present (not all illustrated); Mxp 3 and P1 with one pleurobranch, one arthrobranch, two podobranchs; P2–4 with two pleurobranchs, one arthrobranch, two podobranchs; P5 with one pleurobranch; P1–4 exopod with 15 (15–16), 15 (15–16), 13 (12–14), 12 (12–13) pairs of plumose setae respectively; P5 now of four segments, reaching posterior margin of telson but not uropods; pleopods elongated but unarmed; uropods clearly outreaching posterior margin of telson; telson now rounded posteriorly with spine on posterolateral margin very small but still with three small basal setae.

Nisto (Fig. 9 a–d) N = 4. OL 10.30 mm (range 9.85–10.90 mm); TL 8.13 mm (range 7.70–8.50 mm); CL 3.26 mm (range 3.02–3.40 mm); CW 3.93 mm (range 3.80–4.10); ratio CL:CW = 1:1.21.

Carapace — wider than long, low in profile, with rows of small, sharp spines, surfaces between spine rows mostly smooth; rostrum rounded with dorsal tubercle; acute median gastric tooth posterior to rostrum; single acute, median cardiac tooth lower in profile than gastric tooth, inconspicuous cardiac protuberance lateral to cardiac tooth. Branchial ridge carinate, supporting about ten small, unevenly placed sharp spines, terminating anteriorly as strong, sharp, forward pointing spine behind vaguely defined cervical groove; supraorbital ridge of about nine uneven, small, sharp teeth terminating anteriorly in strong, sharp, antorbital spine. Front emarginate, unarmed between antorbital spines; orbits deep, hiding most of eye from lateral view, lateral and posterior margins of orbit with about four slender, sharp spines. Anterolateral and lateral carapace margins with uneven, acute, forwardly directed spines; small, distinct cervical notch posterolateral to orbit; similarly sized gastrocardiac notch posterior to cervical notch. Posterior margin of carapace sinuous behind ridge between articulations with abdomen. A few scattered setae fringing orbits, lateral carapace margins, branchial ridges, high point of posterior margin.

Antennule — long cigarshaped outer flagellum equal with distal squame of antenna, inner naked flagellum reaching beyond it; proximal segment (in antennular notch) with anterodorsally directed sharp spine.

Antenna — broad, flat with sparse setae dorsally. Anterior margin of terminal segment (distal squame) with four rounded teeth fringed by small sharp spines and setae, plus large sharp tooth and small sharp tooth distomedially. Small penultimate (fifth) segment with about three small, sharp dorsal spines anteriorly; fourth segment (proximal squame) with inconspicuous median dorsal ridge curving forwards to acute anterior, outer margin and anteromedial margin bordered by uneven sharp teeth, medial extension projecting upwards as a short, strong blade with three spines (Fig. 9b); proximal (third) segment with strong, upward pointing median spine (Fig. 9b), sharp anterior spine, sharp, upward pointing lateral spine in front of orbit, second sharp spine directed posterolaterally into front of orbit.

Sternum — fairly flat, somite IV (anterior) with two small, well separated blunt protuberances; somites V–VII with pair of small, sharp spines at lateral margins, somite VIII with single small, sharp lateral spine plus posterolateral corner developed into strong, sharp, downward pointing spine (Fig. 9b, c).

Pereopods — coxae of P1–4 with row of small sharp spines ventrally, meri of P2–5 with row of similar spines ventrally.

Abdomen — terga of abdominal somites II–IV with a median carina; carina of somite II terminates posteriorly as notch; of somite III largest, with posterior 3/4 forming median groove which deepens and opens out posteriorly as a notch; of somite IV also slightly grooved, terminating at posterior notch. Pleura of tergites II–V armed with small, irregular, sharp spines on lateral and posterior borders. Posterior margin of sixth tergite with a median spine and two pairs of sharp spines. Hard anterior portion of telson with two pairs of sharp spines, inner and outer rami of uropods with single sharp spine laterally. Scattered setae on somites as illustrated.

Pleopods — present on somites II–V; biramous, rami fringed by long, plumose setae; endopod with appendix interna reaching distal tip of endopod, cluster of cincinnuli at its tip; basipod without setae.