Paralumbricillus crymodes ( Stephenson, 1922 ), 2024

Klinth, Mårten J., Rota, Emilia, Martinsson, Svante & Erséus, Christer, 2024, Paralumbricillus gen. nov. and other new marine enchytraeids from the North Atlantic, Fauna norvegica 43, pp. 110-134 : 124-128

publication ID	https://doi.org/10.5324/fn.v43i0.5886
persistent identifier	https://treatment.plazi.org/id/038B87E9-FFAF-5108-60CB-D003FB5DFBA1
treatment provided by	Felipe
scientific name	Paralumbricillus crymodes ( Stephenson, 1922 )
status	comb. nov.

Treatment

Paralumbricillus crymodes ( Stephenson, 1922) View in CoL comb. nov.

Figure 10 View Figure 10

Enchytraeus crymodes Stephenson, 1922: pp. 1133–1135 View in CoL , figure 6 Enchytraeus crymodes View in CoL ; Stephenson, 1925: p. 1317.

Marionina crymodes View in CoL ; Nielsen & Christensen, 1959: p. 109.

Lumbricillus crymodes View in CoL ; Coates, 1989: p. 31.

Type locality. Svalbard, Spitsbergen, Bruce City, from among mosses on banks of freshwater pond and near salt marsh, August 2021.

Material examined. ZMBN 110573 View Materials ( CE20719 ) a mature specimen from Svalbard, Spitsbergen, Nordfjorden, Tschermark Stream. Coll. K. Hårsaker, 27 July 2013 . BMNH 1933.5.25.1271–1274, 1279–1282, 1284, 1287, sectioned material on slides from Stephenson’s collection, it is unclear if any of these specimens are part of the type series or if they are from Liefde Bay , another locality on Spitsbergen ( Stephenson 1925). For details on collection site and GenBank accession numbers see Table S1 .

Description of new specimen. Length of first 26 segments 6.4 mm (fixed, amputated specimen); first 15 segments 4.0 mm long; width at clitellum 0.30 mm. Chaetae straight or slightly sigmoid. Dorsolateral bundles with 2–3 chaetae anterior to clitellum, 2–3 chaetae in postclitellar segments. Ventral bundles with 3–4 chaetae anterior to clitellum, 2 chaetae posteriorly. The worm’s longest measured chaetae 60 µm long, about 3–5 µm wide. Clitellum extending over XII–1/2XIII. Head pore not observed.

Coelomocytes, about 25 µm long, round or oval, granulated with distinct nucleus. Paired pharyngeal glands present in IV, V and VI; each pair converging dorsally. Dorsal vessel originating in XIII. Nephridia observed in 7/8–8/9, about 175 µm long. Anteseptale small, consisting of funnel only. Postseptale oval, tapering into posteroventral efferent duct ( Figure 10B View Figure 10 ). Brain with posterior incision.

Male genitalia paired ( Figure 10A View Figure 10 ). Testes originating in XI, with developing sperm seemingly held together by testis sacs, forming irregular lobes extending forwards into X. Sperm funnels in XI, extending forward into X, 655 µm long, 70 µm wide, making them about 9 times longer than wide, funnels tapering towards vasa deferentia. Large parts of vasa irregularly coiled around ovaries in XII, vasa 10–15 µm wide. Penial bulbs compact, 110 µm in diameter. Two mature eggs observed.

Spermathecae ( Figure 10C View Figure 10 ; Table 2) in V, pear-shaped, with ectal duct, and lumen of ectal duct, gradually widening into ampulla. Ampulla round, filled with sperm arranged in tightly packed balls. Ampulla entally connected to oesophagus. Epithelium of duct with cylindrical cells, ampulla with cells not as tall, but more or less cubical. Spermathecae 245 µm long, 25 µm wide at the ectal duct, 115 µm wide at widest part of ampulla. Ectal pore at lateral line, surrounded by rosette of separate glands, together forming a glandular body up to 70 µm wide. Midventral subneural glands observed in XIII–XVI, 70 µm, 50 µm, 60 µm and 65 µm long, respectively.

Geographical distribution including BOLD data. Known from Spitsbergen and Nunavut in Northern Canada. Charlotte Holmquist reported the species from Alaska, USA ( Stöhr 2023), but we have not been able to verify these records .

Remarks. Our single specimen could readily be identified as P. crymodes , a species originally described from a freshwater pond and a salt marsh on Spitsbergen. The only difference we noted is that our specimen has 2–3 chaetae in postclitellar dorsolateral bundles, compared to only 2 in the original description. Our examination of the museum vouchers from Stephenson’s collection confirmed the similarity to our specimen in the shape of the spermathecae, long sperm funnels and thin vasa deferentia. Paralumbricillus crymodes is similar to P. arenarius , which also has long sperm funnels, unlobed penial bulbs and spermathecae with a gradually widening lumen of the ectal duct, and the two species were found close together in our species tree ( Figure 2 View Figure 2 ). Both have been found on Spitsbergen but P. arenarius is more widespread and reported from most of the North East Atlantic, whereas P. crymodes seems to have a more Arctic distribution.

Paralumbricillus lofotensis Klinth & Rota sp. nov. Figure 11 View Figure 11

urn:lsid:zoobank.org:act:89DC1C3D-5E33-4271-9720-E4AE2ADCE90C

Holotype. ZMBN 153285 View Materials ( CE34291 ), Figs 11A, D View Figure 11 , an amputated mature specimen stained in paracarmine and mounted on a slide. COI barcode: BOLD NVENC1605-22 .

Type locality. Rolvsfjorden, Vestvågøy, Lofoten, Nordland, Norway. In coarse sediment in a tidal stream. Coll. C. Erséus & M. Klinth, 8 September 2017 .

Paratypes. ZMBN 129448 View Materials ( CE34290 ) & ZMBN 153286 View Materials ( CE34292 ) one mature and one partially mature specimen from the type locality. For details on collection site and GenBank accession numbers see Table S1.

Etymology. Named after the archipelago Lofoten in Norway.

Diagnosis. Preclitellar bundles regularly with 3 chaetae, sperm funnels about 3.5 times longer than wide, compact penial bulbs, and club-shaped spermathecae with separate bud-like glands surrounding the ectal pore ( Table 2).

Description. Whitish transparent worms. Length of first 26–37 segments 4.6–9.5 mm (fixed, amputated specimens); first 15 segments (2.9)4.0– 4.2 mm long; width at clitellum (0.37) 0.51–0.52 mm. Chaetae straight or slightly sigmoid. Dorsolateral and ventral bundles with 2–3 chaetae anterior to clitellum, and 2 chaetae in postclitellar segments. Each worm’s longest measured chaetae 85–100 µm long, about 6 µm wide. Clitellum extending over XII–1/2XIII. Head pore at 0/1.

Coelomocytes numerous, about 20–35 µm long, oval or spindle-shaped, granulated with distinct nucleus. Paired pharyngeal glands present in IV, V and VI; each pair converging dorsally ( Figure 11A View Figure 11 ). Dorsal vessel originating in XIV. Nephridia observed in 7/8–8/9, about 150–180 µm long. Anteseptale small, consisting of funnel only. Postseptale oval, tapering into thin posteroventral efferent duct ( Figure 11B View Figure 11 ). Brain with posterior incision.

Male genitalia paired ( Figure 11C View Figure 11 ). Testes originating in XI, with some developing sperm seemingly held together by testis sacs, forming irregular lobes, other cysts of developing sperm floating free in XI. Sperm funnels in XI, 195–215 µm long, 60–65 µm wide, making them about 3–3.5 times longer than wide, funnels tapering towards vasa deferentia. Large parts of vasa irregularly coiled around ovaries in XII, vasa 6 µm wide. Penial bulbs compact, 85–95 µm in diameter. Two mature eggs observed.

Spermathecae ( Figure 11D View Figure 11 ) in V, club-shaped, with ectal duct suddenly widening into ampulla. Ampulla round, with sperm arranged in a circle perpendicular to the duct. Ampulla connected to oesophagus via ental duct. Epithelium of duct with cylindrical cells, ampulla with cubical cells. Spermathecae 150–160 µm long, 30–35 µm wide at the ectal duct, 75–90 µm wide at widest part of ampulla. Ectal pore at lateral line, surrounded by rosette of separate bud-like glands, entire arrangement of these glands about 65 µm wide. No midventral subneural glands observed.

Geographical distribution including BOLD data. Only known from the type locality in Nordland, Northern Norway .

Remarks. This species can be distinguished from most other members of Paralumbricillus by the combination of compact penial bulbs and several preclitellar bundles with more than two chaetae. Among the species of Paralumbricillus that share these characters, P. eltoni ( Stephenson, 1924) and P. muscicolus ( Stephenson, 1924) have shorter sperm funnels than P. lofotensis sp. nov. The two species that most resemble P. lofotensis sp. nov. are P. eudioptus ( von Bülow, 1955) and P. nielseni ( Nurminen, 1965) . Unfortunately, the original description of P. nielseni is brief and without illustrations, but it seems that this species can be separated from P. lofotensis sp. nov. for never having more than 2 chaetae in preclitellar dorsolateral bundles. Paralumbricillus eudioptus can be distinguished from P. lofotensis sp. nov. by having postclitellar bundles with more than 2 chaetae and by the shape of its spermathecae, which have a strange internal structure ( Table 2).

Paralumbricillus bicornis Klinth & Rota sp. nov. Figure 12 View Figure 12

urn:lsid:zoobank.org:act:B0F118D1-C246-4677-AAEA-9C7C09AB7FEF

Lumbricillus sp. H ; Klinth et al. 2017a; Klinth et al. 2017b, figure 22.

Holotype. ZMBN 153402 View Materials ( CE25014 ), Figs 12A–C View Figure 12 , an amputated mature specimen stained in paracarmine and mounted on a slide. COI barcode: BOLD NOENC410-18 .

Type locality. Holmsundsfjorden Bay, 2 km south of Kjellingbrua Bridge, Kjøpstad, Gildeskål, Nordland, Norway. Upper intertidal, rock pool, gravel and grey sand. Coll. C. Erséus & E. Willassen, 11 September 2014.

Paratypes. ZMBN 107947 View Materials ( CE24967 ) & ZMBN 107948 View Materials ( CE24968 ) two partially mature specimens from the type locality. For details on collection site and GenBank accession numbers see Table S1.

Other material examined. ZMBN 107945 ( CE 23136), ZMBN 129442 ( CE 34247), ZMBN 153284 ( CE 34248), ZMBN 129452 ( CE 34308) four partially mature specimens from Norway. For details on collection site and GenBank accession numbers see Table S1.

Etymology. Latin, from bi -, two, and cornu for horn, describing the horns extending from the penial bulb.

Diagnosis. The tripartite penial bulbs, with a central round bulb and two horns or lobes extending one anteriorly and one posteriorly, distinguishes this species from other Paralumbricillus species.

Description. Length of first 29–33 segments 4.1–7.9 mm (fixed, amputated specimens); first 15 segments 2.1–3.0 mm long; width at clitellum 0.38–0.56 mm. Chaetae straight or slightly sigmoid. Dorsolateral and ventral bundles with 2–3 chaetae anterior to clitellum, and 2 chaetae in postclitellar segments. Each worm’s longest measured chaetae 70–95 µm long, about 5 µm wide. Clitellum extending over XII–1/2XIII. Head pore at 0/1.

Coelomocytes numerous, about 15–20 µm long, round, oval or spindle-shaped granulated with distinct nucleus. Paired pharyngeal glands present in IV, V and VI, third pair sometimes extending back into VII; each pair converging dorsally. Dorsal vessel originating in XIII. Nephridia observed in 7/8–8/9, and from 12/13 rearwards, about 100–145 µm long. Anteseptale small, consisting of funnel only. Postseptale oval, tapering into thin posteroventral efferent duct ( Figure 12A View Figure 12 ). Brain with posterior incision.

Male genitalia paired ( Figure 12C View Figure 12 ). Testes originating in XI, with some developing sperm seemingly held together by testis sacs, forming irregular lobes, other cysts of developing sperm floating free in X–XI, sometimes XII. Sperm funnels in XI, 465–505 µm long, 40–65 µm wide, making them about 7–12 times longer than wide, funnels tapering towards vasa deferentia. Large parts of vasa irregularly coiled around ovaries in XII, vasa 10–20 µm wide. Penial bulbs tri-partite with round central mass, 65–105 µm in diameter, from which two smaller lobes extend, one anterior and one posterior, both lobes more ventromedial than the central lobe, vas entering central lobe ( Figure 12D View Figure 12 ). No fully mature eggs observed.

Spermathecae ( Figure 12B View Figure 12 ) in V, club-shaped, with long ectal duct suddenly widening into ampulla. Ampulla oval, entally connected to oesophagus. No sperm observed in it. Spermathecae 180–190 µm long, 25–35 µm wide at the ectal duct, 55–60 µm wide at widest part of ampulla. Ectal pore at lateral line, surrounded by rosette of separate glands, glandular rosette up to 50–55 µm wide. Two midventral subneural glands in XV–XVI, 45–100 µm and 50–95 µm long, respectively.

Geographical distribution including BOLD data. Only known from Nordland and Troms, Norway .

Remarks. The partially mature penial bulb observed by Klinth et al. (2017b, figure 22E) appeared bilobed, but with additional material the fully mature bulbs turned out to be actually tripartite, with a central round bulb and two horn-like lobes. This makes this new species less similar to P. westheidei ( Kossmagk-Stephan, 1983) , which was previously suggested as a possible candidate for our specimens ( Klinth et al. 2017b). Paralumbricillus dubius ( Stephenson, 1911) also has penial bulbs with two horn-like lobes, but unlike P. bicornis sp. nov. where the horns extend from a central bulb, the bulbs in P. dubius are divided in two lobes and each lobe extends into a horn. Our species tree ( Figure 2 View Figure 2 ) shows P. bicornis sp. nov. as genetically closest to P. lofotensis sp. nov., which has a similar chaetal pattern and spermathecal morphology, but the latter species has much shorter sperm funnels (only 3-3.5 times longer than wide) and compact penial bulbs (lacking horns).

Paralumbricillus sanguineus Klinth & Rota sp. nov. Figure 13 View Figure 13

urn:lsid:zoobank.org:act:BAFB0A34-FC7D-4AD7-AFA3-84486770406D

Holotype. ZMBN 129381 View Materials ( CE33777 ), Fig 13C View Figure 13 , an amputated mature specimen stained in paracarmine and mounted on a slide. COI barcode: BOLD NOENC418-18 .

Type locality. Damsgård, Andenes, Andøya, Nordland, Norway. Mid-intertidal pebbles, sand and shells. Coll. C. Erséus & M. Klinth, 6 September 2017 .

Paratype. ZMBN 129380 View Materials ( CE33776 ) a partially mature specimen from the type locality. For details on collection site and GenBank accession numbers see Table S1.

Other material examined. NTNU-VM 74055 View Materials ( CE29066 ) , NTNU-VM 74080 View Materials ( CE29284 ) , ZMBN 129189 View Materials ( CE32243 ) , ZMBN 153279 View Materials ( CE32236 ) , ZMBN 153280 View Materials ( CE32279 ) & ZMBN 153281 View Materials ( CE32280 ) two partially mature and four immature specimens from Norway. For details on collection site and GenBank accession numbers see Table S1 .

Etymology. From sanguis, Latin for blood, referring to the conspicuous dorsal and ventral blood vessels observed in this species.

Diagnosis. This species can be separated from other members of the genus by the combination of bilobed penial bulbs (with anterior and posterior lobes) and club-shaped spermathecae with very narrow ectal ducts. The conspicuous blood vessels may also help in the identification, but they are more apparent in immature specimens than in mature specimens. This is also one of the longest and most slender species in Paralumbricillus , with some specimens reaching more than 70 segments.

Description. Length of first 27–69 segments 5.1–16.7 mm (fixed, amputated specimens); first 15 segments 2.5–3.1 mm long; width at clitellum 0.24–0.29 mm. Chaetae straight or slightly sigmoid. Dorsolateral bundles with (2)3(4) chaetae anterior to clitellum, and 2(3) chaetae in postclitellar segments. Ventral bundles with (2)3 chaetae anterior to clitellum, and 2(3) chaetae in postclitellar segments. Each worm’s longest measured chaetae 65–75 µm long, about 5 µm wide. Clitellum extending over XII–1/2XIII. Head pore at 0/1.

Coelomocytes numerous, about 10–20 µm long, round or oval, granulated with distinct nucleus. Paired pharyngeal glands present in IV, V and VI; each pair converging dorsally ( Figure 13A View Figure 13 ). Dorsal and ventral vessels conspicuous throughout, stained yellow in paracarmine; origin of dorsal vessel uncertain but seems posterior to XIV. Nephridia observed in 7/8–9/10 and in postclitellar segments, about 120–165 µm long. Anteseptale small, consisting of funnel only. Postseptale oval, tapering into thick posteroventral efferent duct ( Figure 13B View Figure 13 ). Brain with posterior incision.

Male genitalia paired ( Figure 13C View Figure 13 ). Testes originating in XI, with developing sperm seemingly held together by testis sacs, forming large compact mass extending forwards into IX and backwards into XII, some cysts of developing sperm free floating in XI. Sperm funnels in XI, 110–155 µm long, 45–95 µm wide, making them about 1.5–2.5 times longer than wide, funnels tapering towards vasa deferentia. Large parts of vasa irregularly coiled around ovaries in XII, vasa 10 µm wide. Penial bulbs bilobed with anterior and posterior lobes, vasa entering where lobes fuse ventrally, each lobe about same width, their combined length about 65–80 µm. No mature eggs observed.

Spermathecae ( Figure 13D View Figure 13 ) in V, club-shaped, with very thin ectal duct suddenly widening into round ampulla, reminiscent of some Fridericia Michaelsen, 1889 or Marionina species. Ampulla connected to oesophagus via ental duct. No sperm observed in it. Spermathecae 100–165 µm long, 10–15 µm wide at the ectal duct, 60 µm wide at widest part of ampulla. Ectal pore at lateral line, surrounded by rosette of separate glands, rosette up to 35–60 µm wide. Two midventral subneural glands in XIII–XIV, 75 µm and 60 µm long, respectively.

Geographical distribution including BOLD data. Only known from the middle of Norway (Møre og Romsdal, Trøndelag and Nordland) .

Remarks. This species is unusually long and slender compared to other species of Paralumbricillus or most Lumbricillus , and is in this way more alike the species of Grania and Randidrilus Coates & Erséus, 1985 . Another striking feature are the conspicuous blood vessels, but the bilobed penial bulbs and thin spermathecal ducts also stand out. The lack of sperm in the spermathecae does suggest that the specimens were not fully mature and that the shape of the spermathecae was not fully developed but the well-developed male genitalia and clitellum contradict this. The bilobed penial bulbs are somewhat similar to those of P. westheidei , but that species can be separated by having much longer sperm funnels. In our species tree ( Figure 2 View Figure 2 ), P. sanguineus sp. nov. was found in a clade together with P. dubius and P. sp. “ Norway ” with maximum support, but with large genetic distance between the species.