Lebbeus sanctipauli
Creators: name: Komai, Tomoyuki
name: Lemaitre, Rafael
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Hippolytidae
Lebbeus
Lebbeus sanctipauli

description: Lebbeus sanctipauli (Brandt, 1851)
(Figs. 1–4)
Hippolyte St. Pauli Brandt, 1851: 118, pl. 5, fig. 19 [type locality: Beeringschen Meere bei Pauls-Insel].
Spirontocaris polaris. –– Rathbun 1904: 73 (in part).
Hetairus polaris. –– Brashnikov 1907: 148, fig. 17. –– Kobjakova 1936: 222; 1937: 116.
Lebbeus polaris. –– Holthuis 1947: 9 (in part). –– Vinogradov 1950: 205, fig. 44A, G. –– Hayashi 1992: 130 (in part), fig. 12b, c; 1993: 7 (in part), fig. 236d, 237d, 238d. –– De Grave & Fransen 2011: 426 (in part).
Material examined. Alaska. USNM 15353, off St. Paul Island, Pribilof Islands, Bering Sea, 2 June 1890, coll. W. Palmar; USNM 27351, 5 females (cl 7.7–10.4 mm), similar locality, 57°24'N, 170°16'W, 11–16 m, 24 July 1874, coll. W. Dall; USNM 27367, 3 females (cl 9.2–11.6 mm), similar locality, 56°58.0'N, 170°09.0'W, 46 m, U.S. Fish Commission “Albatross”, stn 3558, 3 September 1893, beam trawl; USNM 27369, 1 female (cl 7.1 mm), SW of Pribilof Islands, 56°32.0'N, 172°40.0'W, 0–148 m, U.S. Fish Commission “Albatross”, stn 3602, 10 August 1895; USNM 27345, 2 females (cl 6.7, 7.7 mm), 1 male (cl 6.0 mm), Popoff Strait, Alaska Peninsula, 55°16.2'N, 160°29.31'W, coll. W. Dall; USNM 27357, Belkofski Bay, Alaska Peninsula, 55°04.49'N, 167°07.32'E, 1880, coll. W. Dall; USNM 27364, 1 female (cl 8.0 mm), NE of Cape Leontovich, Alaska Peninsula, 55°44.20'N, 162°17.30'E, 40 m, U.S. Fish Commission “Albatross”, stn 3275, 27 June 1890, beam trawl; USNM 27343, 1 female (cl 4.4 mm), Iliuliuk, Unalaska Island, Aleutian Islands, 53°53.0'N, 166°30.0'W, 18.3 m, 1871, coll. W. Dall; USNM 27365, Umnak Pass, Unalaska Island, 53°28.45'N, 167°23.50'W, 64 m, U.F. Fish Commission “Albatross”, stn 3322, 18 August 1890, beam trawl; USNM 27347, 3 males (cl 5.2–5.6 mm), Adak Island, Aleutian Islands, 51°47.4'N, 176°38.25'W, 16–29 m, coll. W. Dall. Studied by Rathbun (1904).
Siberia. USNM 27358, 1 male (cl 7.4 mm), Plover Bay, Chukchi Peninsula, Bering Sea, 64°25'N, 173°24'W, 27–37 m, September 1880, coll. W. Dall, studied by Rathbun (1904).
Kamchatka. USNM 27338, 1 male (cl 5.5 mm), Commander Islands, western Bering Sea, 55°00'N, 166°15'E, 1885, coll. N. Grebnitzky, studied by Rathbun (1904).
Kuril Islands. TUMST, 1 female (cl 7.9 mm), off Shimshir Island, Kurile Islands, 50–60 m, 1937, studied by Hayashi (1992, 1993).
Japan. CBM-ZC 10176, 1 female (cl 8.7 mm), off Katsurakoi, Kushiro, Hokkaido, 38 m deep, 11 September 1990; TUMST, 1 male (cl 7.0 mm), 1 female (cl 8.1 mm), near Hokkaido, no other data available, studied by Hayashi (1992, 1993).
Type material. Holotype, female, probably deposited in the Zoological Institute, St. Petersburg (cf. Komai & Eletskaya 2008). Not examined.
Diagnosis. Rostrum (Figs. 1, 2A, B) directed forward, overreaching distal end of antennular peduncle, but not reaching distal margin of antennal scaphocerite, 0.9–1.1 times carapace length, sexually dimorphic in armature; in female, dorsal margin armed with 3–4 moderately small teeth, including 1–3 on proximal 0.3–0.6 of rostrum and 2 postrostral; in male, dorsal margin unarmed; ventral margin expanded into blade-like lamina in distal half, armed with 2 or 3 small teeth in both sexes. Carapace (Figs. 1, 2A, B) with low postrostral median ridge extending to midlength; posteriormost postrostral tooth located at 0.2 of carapace length; supraorbital spine arising at level of posterior margin of orbit; no notch present below base of supraorbital spine; suborbital lobe shorter than antennal spine; anterolateral margin between antennal spine and pterygostomial angle slightly sinuous; small pterygostomial spine present in females, absent in males. Pleomeres 1–3 pleura rounded, pleura 4 and 5 each with small posteroventral spine (Fig. 1). Telson (Fig. 2C) with 3–5 dorsolateral spiniform setae on either side; posterior margin with tiny median spine flanked by 3 pairs of spiniform setae and 1 mesial pair of stiff setae (Fig. 2D). Corneal width slightly more than 0.2 carapace length; ocellus (= nebenaugen) present (Fig. 2B). Antennular peduncle reaching (female: Fig. 2B) or slightly overreaching (male: Fig. 4A) midlength of scaphocerite; article 1 with 1 distolateral spine; stylocerite reaching midlength of article 3; article 2 and 3 each with 1 small spine distally. Antennal carpocerite reaching midlength of scaphocerite (Fig. 1); scaphocerite with distolateral spine far exceeded by strongly produced distal lamella (Fig. 2B). Strap-like epipods present on maxilliped 3 and pereopod 1–3 (Fig. 1). Pereopod 3 (Figs. 1, 3H) reaching scaphocerite by tip of propodus; dactylus (Fig. 3I) 0.2 times as long as propodus, stout, armed with 3 or 4 accessory spiniform setae on flexor margin, ultimate seta distinctly longer and wider than other setae; merus with 4–6 spiniform setae on lateral face.
Description. Females. Body (Fig. 1) moderately robust; integument moderately firm, surface glabrous.
Rostrum (Fig. 2A, B) straight, directed forward, overreaching distal end of antennular peduncle, but falling far short of distal margin of antennal scaphocerite, 0.9 times as long as carapace; dorsal margin armed with 3 or 4 moderately small teeth, including 1 or 2 on proximal part of rostrum proper and 2 postrostral, at least distal half unarmed, tip acuminate; ventral margin expanded into broad, blade-like convexity in distal half, armed with 2 or 3 well-spaced, small teeth in distal one-third; lateral carina generally obsolescent.
Carapace (Figs. 1, 2A, B) with low postrostral median ridge, extending to midlength; posterior postrostral spine located at about anterior 0.2 of carapace length; dorsal margin in lateral view slightly convex; lateral surface smooth, no trace of ridge on branchial region; supraorbital spine moderately small, directed forward, arising just at rostral base; orbital margin evenly concave; no notch below base of supraorbital spine; suborbital lobe distinct, blunt, falling far short of antennal spine; anterolateral margin between antennal and pterygostomial spines gently sinuous with shallow concavity below antennal spine; pterygostomial spine small.
Pleon (Fig. 1) dorsally rounded. Pleomere 2 with distinct anterior transverse groove on tergum. Pleura of anterior three somites broadly rounded; pleuron 4 with small posteroventral spine; pleuron 5 with moderately large posteroventral spine. Pleomere 6 1.7 times as long as high, bearing small posteroventral spine; posterolateral process terminating in small spine. Telson (Fig. 2D) 1.2 times as long as pleomere 6, about 3 times as long as greatest width, tapering to broadly triangular posterior margin, bearing 3 or 4 dorsolateral spiniform setae on either side; posterior margin with minute median spine flanked by 1 mesial pair of stiff setae and 2 (left) or 3 (right) unequal spiniform setae (Fig. 2E).
Eye (Figs. 1, 2B) subpyriform with eyestalk slightly narrowing proximally; cornea slightly wider than eyestalk, its maximum width slightly more than 0.2 of carapace length; ocellus present.
Antennular peduncle (Figs. 1, 2B) reaching midlength of antennal scaphocerite. Article 1 distinctly longer than distal two articles combined, dorsodistal margin armed with 1 slender spine; stylocerite long, slender, reaching midlength of peduncular article 3, gradually tapering to acute tip, mesial margin slightly sinuous. Article 2 about 0.4 length of article 1, with l moderately small dorsolateral distal spine. Article 3 less than half as long as article 2, bearing 1 moderately small dorsodistal spine. Lateral flagellum with thickened aesthetasc-bearing portion about half-length of carapace.
Antenna (Figs. 1, 2B) with basicerite bearing moderately small ventrolateral distal spine; carpocerite reaching midlength of scaphocerite. Scaphocerite 0.9 times as long as carapace and 2.8 times as long as wide; lateral margin faintly sinuous; distolateral spine far exceeded by strongly produced distal lamella.
Mouthparts not dissected, but without distinctive features on external observation.
Maxilliped 3 (Fig. 3A–C) overreaching antennal scaphocerite by half-length of ultimate article.Antepenultimate article with small spiniform seta located at tip of submarginal tubercle adjacent to distolateral margin; 1 small spiniform seta at ventrolateral distal angle; lateral surface with longitudinal row of evenly spaced stiff setae along blunt ridge adjacent to dorsal margin. Ultimate article about 3.5 times as long as penultimate article (= carpus), tapering, with scattered tufts of short stiff setae on lateral surface; distal 0.2 circumscribed by small spiniform setae, all darkly pigmented.
Strap-like epipods present on maxilliped 3 and pereopods 1–3 (epipods on maxilliped 3 and pereopods 1 each terminally hooked, while epipods on pereopods 2 and 3 simple) (Fig. 1), and corresponding setobranchs only on pereopods 1 and 2.
Pereopod 1 (Fig. 3D–F) moderately stout, just reaching distal margin of scaphocerite.Merus with minute spine on dorsal margin near articulation with ischium; ventral margin with row of minute spiniform setae proximally. Carpus cup-like, slightly widened distally, slightly shorter than palm; mesial surface subdistally with grooming apparatus consisting of shallow concavity and complex of short stiff setae. Chela about 1.4 times as long as carpus; palm subcylindrical, 2.9 times as long as wide; fixed finger terminating in single, darkly pigmented, basally demarcated claw; dactylus 0.6 times as long as palm, terminating in 2 darkly pigmented, basally demarcated claws.
Pereopod 2 (Fig. 3G) overreaching antennal scale by about 0.3 length of carpus. Merus subequal in length to ischium. Carpus divided into 7 segments, segment 3 longest. Chela subequal in length to distal 3 carpal articles combined; dactylus shorter than palm.
Pereopods 3–5 moderately long and slender for genus, similar in shape. Pereopod 3 (Fig. 3H) overreaching antennal scaphocerite by half length of propodus; ischium unarmed; merus armed with 6 spiniform setae, increasing in size distally, on lateral surface adjacent to ventral margin; carpus about half length of propodus; propodus with single row of evenly spaced slender spiniform setae on flexor margin and scattered tufts of short setae on extensor surface; dactylus (Fig. 3I) about 0.2 times as long as propodus, stout (2.9 times as long as high), terminating in stout, pigmented unguis, flexor margin armed with 4 accessory spiniform setae over entire length, these setae noticeably increasing in length distally, distalmost setae distinctly shorter and narrower at base than unguis. Pereopod 4 (Fig. 3J) reaching antennal scaphocerite by tip of propodus; merus with 5 spiniform setae; dactylus with 4 accessory spinules. Pereopod 5 (Fig. 3K) reaching midlength of scaphocerite by tip of propodus; merus with 1 spiniform seta near ventrodistal angle subterminally; propodus with brush-like setal row consisting of grooming apparatus, distally on flexor margin; dactylus less than 0.2 times as long as propodus, with 3 accessory spinules.
Pleopods 1–5 without distinctive features. Uropod (Fig. 1) overreaching posterior end of telson; protopod with moderately strong posterolateral spine; exopod armed with small spiniform seta just mesial to small posterolateral spine.
Male characteristics. Rostrum (Fig. 4A, B) with dorsal margin slightly sloping distally, unarmed, but with 2 obsolescent protuberances posterior to orbital margin. Carapace pterygostomial margin rounded, unarmed (Fig. 4A, B). Antennule (Fig. 4A) with peduncle slightly overreaching midlength of antennal scaphocerite; stylocerite reaching distal margin of peduncular article 2; flagella better developed than in females, inner flagellum elongate, stout, longer than carapace. Pleopod 1 endopod (Fig. 4C) subtriangular, tapering distally to terminal appendix interna, mesial margin with row of minute curved setae extending distally to level of distal 0.2 length. Pleopod 2 with appendix masculina (Fig. 4D) about 0.8 length of appendix interna, bearing numerous stiff setae on mesial face to terminus.
Colouration in life. Unknown.
Distribution. North Pacific, ranging from Hokkaido, Japan to Bering Sea; at depths of 11–64 m, possibly to 148 m.
Remarks. In this study, specimens from the North Atlantic (Davis Strait and Norwegian Sea), which agree well with the original description of L. polaris by Sabine (1824), were examined for comparison (see “Material and method). The present North Pacific specimens, including those studied by Rathbun (1904) and Hayashi (1992, 1993) as L. polaris, differ from the North Atlantic specimens in the following points.
(1) Rostral dorsal teeth in females are fewer in the northwestern Pacific specimens than in the North Atlantic specimens, four in the former, and six to eight in the latter; the distal 0.6–0.8 of the dorsal margin is unarmed in the Northwestern Pacific specimens (Figs. 1, 2A versus Fig. 5A, B). Previous studies show wider variation in the number of the dorsal rostral teeth in specimens from the North Atlantic (e.g., Smith 1879). The significance of this character might be discounted, although still useful as a diagnostic character.
(2) The ventral blade of the rostrum in males is better developed in the northwestern Pacific specimen than in the North Atlantic specimens (Fig. 4A, B versus Fig. 5F, G).
(3) Dorsolateral spiniform setae are fewer in the northwestern Pacific specimens than in the North Atlantic specimens, three to five on either side in the former versus six to 12 in the latter (Fig. 2B versus Fig. 5C).
(4) The stylocerite on the antennular peduncle article 1 in females overreaches the distal margin of the article 2 in the North Pacific specimens, rather than not reaching it in the North Atlantic specimens (Figs. 1, 2B versus Fig. 5A).
(5) The pereopods 3–5 are stouter in the northwestern Pacific specimens than in the North Atlantic specimens (Fig. 3H versus Fig. 5D); accessory spiniform setae on the dactylus flexor margin are fewer in the northwestern Pacific specimens than in the North Atlantic specimens (three or four versus five to seven) (cf. Fig. 3J versus Fig. 5E).
(6) There is a strap-like epipod on the pereopod 3 coxa in the northwestern Pacific specimens, whereas no epipod is present on that appendage in the North Atlantic specimens (Fig. 1 versus Fig. 5D).
These morphological differences warrant the recognition of the North Pacific form as a separate species from L. polaris. Brandt’s (1851) original description of “ Hippolyte St. Pauli ” is brief, lacking important details such as the number of the telson dorsolateral spiniform setae or the presence or absence of epipods on pereopods. Nevertheless, Brandt differentiated his new taxon on the basis of the broader rostrum with a greatly unarmed dorsal margin and relatively stout pereopods, which are consistent with the present specimens. Consequently, we think it is rational to apply Brandt’s (1851) taxon to the present North Pacific specimens, removing it from the synonymy of L. polaris. The species epithet should be spelled as “ sanctipauli ” according to the ICZN code 32.5.2.4 (ICZN 1999).
Lebbeus polaris, with which L. sanctipauli has been synonymized, is a well-known species that has been considered to exhibit a circumpolar distribution including the North Atlantic and the North Pacific oceans (e.g., Rathbun 1904; Brashnikov 1907; Kobjakova 1937; Holthuis 1947; Vinogradov 1950; Smaldon 1979; Wicksten 1978, 1990; Williams 1984; Squires 1992). As shown by Komai et al. (2021), more than one species are involved among 31 sequences of the mitochondrial COI gene, which are referred to as L. polaris in the GenBank database. It should be noted that there are no voucher specimens from the North Pacific. In fact, there are nine available names presently placed in the synonymy of Lebbeus polaris (cf. De Grave & Fransen 2011) other than L. sanctipauli: Hippolite borealis Ross, 1835 [type locality: off Elizabeth Harbour, 80 fms]; Lebbeus orthorhynchus White, 1847 [type locality not indicated]; Hippolyte cultellata Norman, 1867 [type locality: the Minch, Scotland]; Hippolyte incerta Buchholz, 1874: 272 [type locality: Ostgrönland]; Hippolyte Amazo Pfeffer, 1886 [type locality: CumberlandSund, Baffins Land, 66°35'40''N 67°19'15''W]; Hetairus debilis Bate, 1888 [type locality: Challenger stn 49, S of Halifax, Nova Scotia, 43°03'N 63°39'W, 85 fms]; Hetairus tenuis Bate, 1888: 613; Plate 109, fig. 3. [type locality: Challenger stn 49, 43°3'N 63°39'W, S of Halifax, Nova Scotia, 85 fms]; Hippolyte projecta Bate, 1888 [type locality: Challenger stn 49, 43°3'N 63°39'W, S of Halifax, Nova Scotia, 85 fms]; and Hippolyte mysis Birulya, 1898 [White Sea, SW coast of Kandalak Bay, Kovda]. All but Lebbeus orthorhynchus were originated from the North Atlantic or Arctic. The type locality of Lebbeus orthorhynchus was not indicated, but the name was placed under Hippolyte polaris (cf. White 1847: 76), suggesting they were synonymous. Future study may eventually reveal that at least some of these taxa are actually valid. A revision of L. polaris is necessary, but such an extensive study largely requiring examination of material from the North Atlantic Ocean is beyond the scope of this short article.
In this study, we reidentified specimens studied by Rathbun (1904) and Hayashi (1992, 1993) as L. polaris with L. sanctipauli. Records of Lebbeus polaris from the North Pacific (i.e., Brashnikov 1907; Kobjakova, 1936, 1937; Vinogradov 1950) are at least partially referred to L. sanctipauli, referring to our findings. In particular, Brashnikov (1907: fig. 17) and Vinogradov (1950: fig. 44A, B) presented figures of carapaces (female and male) they identified with L. polaris (as Hetairus Bate, 1888 in the former), which are well consistent with the present specimens of L. sanctipauli.
Hayashi (1992) examined one female specimen from the Bering Sea, in addition to the two lots here reexamined, but that specimen was not available for examination. Hayashi’s (1992) specimen from the Bering Sea is different from the present specimens referred to L. sanctipauli in having five dorsal rostral teeth, of which the anteriormost one is located distal to the midlength of the rostrum, and the antennular stylocerite not overreaching the distal margin of the antennular peduncle 2 article. Accessory spiniform setae on the pereopod 3–5 dactyli seem to be more numerous (Hayashi 1992: fig. 12a), though not specifically mentioned. It is likely that the specimen might represent a species other than L. sanctipauli.
Wicksten (1978) identified one specimen from off California with L. polaris, following the synonymy of Spirontocaris unalaskensis Rathbun, 1902 with L. polaris, proposed by Holthuis (1947). At present, L. unalaskensis is considered as a valid species (Hayashi 1992; De Grave & Fransen 2011), and then Wicksten’s (1977) specimen could be referred to L. unalaskensis for the time being.
Cha et al. (2001) reported L. polaris from Korean waters, with a photograph of an overall habitus of a female specimen in preservative and one line drawing of carapace, although detailed data of voucher specimens were not provided. The photographed specimen is different substantially from both L. sanctipauli and L. polaris in the slender rostrum with a poorly developed ventral blade and slender dactyli of the pereopods 3. On the other hand, the illustrated carapace resembles that of L. sanctipauli in having dorsal rostral teeth restricted to the proximal half of the rostrum and a well-developed ventral blade of the rostrum.
At present, there are no certain records of L. polaris in the North Pacific Ocean. As mentioned above, there is no doubt that more than one species are mixed up under L. polaris judging from the high genetic divergence among COI sequences registered in the GenBank database. Integrative approach would be advisable to clarify the taxonomic problems relating to L. polaris and closely allied taxa.
description: Published as part of Komai, Tomoyuki & Lemaitre, Rafael, 2022, Reinstatement of " Hippolyte St. Pauli " Brandt, 1851 as a valid species of Lebbeus White, 1847 (Decapoda: Caridea: Thoridae), pp. 350-360 in Zootaxa 5168 (3) on pages 351-357, DOI: 10.11646/zootaxa.5168.3.6, http://zenodo.org/record/6882891