Simorhynchotus antennarius
Creators: name: Zeidler, Wolfgang
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Lycaeidae
Simorhynchotus
Simorhynchotus antennarius

description: Simorhynchotus antennarius (Claus, 1871)
(Figs 22–23)
Simorhynchus antennarius Claus, 1871: 156–157.— Claus 1879: 189 (43).— Bovallius 1887: 34.— Claus 1887: 65, pl. 17, figs 9–19.
Simorhynchotus antennarius. — Stebbing 1888: 1572–1575, pl. 200.— Bovallius 1890: 48 (key).— Spandl 1924: 267.— Stephensen 1925: 185–186, 230 (tab.), fig. 72.— Spandl 1927: 211 (incl. key), fig. 32.— Pirlot 1929: 161.— Barnard 1930: 433.— Barnard 1931: 130.— Barnard 1937: 191–192.— Pirlot 1938: 366, (38).— Bulycheva 1955: 1048 (tab.).— Hurley 1955: 182.— Reid 1955: 28.— Fage 1960: 11–14, figs 1–3.— Grice & Hart 1962: 300.— Hoenigman 1963: 593.— Siegfried 1963: 10.— Pillai 1966a: 171–173, pl. 1, fig. A; figs 1–2.—Hure et al. 1969: 603, 605 (tabs.).— Lewis & Fish 1969: 9.— Dick 1970: 73, fig. 14 (part).— Yoo 1971: 64.— Yoo 1972: 175, fig. 7.— Tashiro & Jossi 1972: fig. 9 (map), 20 (list), 35 (tab.).— Thurston 1976: 388–390 (tabs.), 439–440, 464 (tab.), fig. 24 (distribution).—Schulenberger 1977: 379 (tab.).— Tranter 1977: 649 (tab.), 651.— Zeidler 1978: 31, fig. 30.— Laval 1980: 23 (tab.).— Stuck et al. 1980: 367.— Brusca 1981: 32 (key), 45, fig. 22c-d.— Vinogradov et al. 1982 /1996: 391–392/483–484, fig. 211.— Zeidler 1984: passim.— Vinogradov 1990: 76, 94 (tab.).— Vinogradov 1991: 261 (tab.).— Vinogradov 1993: 45 (tab.).— Lin & Chen 1994: 118 (list).— Montú 1994: 133 (list).— Lin et al. 1995: 120, 122 (tab.).— Nair 1995: 8–9, pl. 1a, fig. B; pl. 6.— Shih & Chen 1995: 212–215, figs 140–141.— Lin et al. 1996: 230 (tab.).— Montú 1998: 601.— Zeidler 1998: 107.— Barkhatov et al. 1999: 808 (tab.).— Vinogradov 1999: 1148 (tab.), 1195, fig. 4.142.— Lowry 2000: 327 (list).— Gasca & Shih 2001: 496 (tab.).— Lima & Valentin 2001: 473 (list), 474 (tab.).— Escobar-Briones et al. 2002: 367 (list).— Gasca 2003a: 308 (tab.).— Gasca & Shih 2003: 95 (tab.).— Gates et al. 2003: 323.—Gasca 2004: 997 (tab.).— Gasca & Suárez-Morales 2004: 26 (tab.).— Vinogradov et al. 2004: 16, 25 (tab.).— Brusca & Hendrickx 2005: 152 (list).— Zelickman 2005: xvii (list), fig. 41a-b (pp. 256–259).— Garcia-Madrigal 2007: 158, 192 (list).— Gasca 2007: 120 (tab.).— Gasca & Franco-Gordo 2008: 569 (tab.).— Costa et al. 2009: 101, 196, fig. 184.— Gasca 2009a: 89 (tab.).— Gasca 2009b: 66 (tab.).— Gasca 2009c: 218 (tab.).— Gasca et al. 2009: 1497 (tab.).— Lavaniegos & Hereu 2009: passim.— LeCroy et al. 2009: 969 (tab.).— Valencia & Giraldo 2009: 268 (tab.), passim.— Mori et al. 2010: 6, 10 (lists).— Gasca & Morales-Ramírez 2012: 229, fig. 3C.—Gasca et al. 2012: passim.— Valencia & Giraldo 2012: 1492 (tab.).— Valencia et al. 2013: 51 (tab.).— Gasca & Franco-Gordo 2014: 76 (list).— Gasca et al. 2014: 4 (tab.), 6.— Gómez-Gutiérrez et al. 2014: 1019 (tab.).— Lavaniegos 2014: 5 (tab.), fig. 5 (dendrogram).— Espinosa-Leal & Lavaniegos 2016: passim.— Lavaniegos 2016: passim.— Souza et al. 2016: 344 (tab.).— Zeidler 2016: fig. 21 (p. 54).— Hereu et al. 2020: passim.— Lavaniegos 2020: passim.— Espinosa-Leal et al. 2021a: passim.— Espinosa-Leal et al. 2021b: passim.—Véliz et al. 2121: passim.
Simorhynchus Lilljeborgi Bovallius, 1887: 34.
Simorhynchotus Lilljeborgi. — Bovallius 1890: 48 (key), 52–54, text figs 25, 28, 34, 50, 67, 70, 76; pl. 1, figs 1–7.— Chevreux 1900: 160.
Simorhynchotus lilljeborgi. — Spandl 1927: 211 (key), 212, fig. 33.— Dakin & Colefax 1940: 125–126, fig. 215.
Simorhynchotus Stebbingi Bovallius, 1890: 48 (key), 50–52.
Type material. Type material of Simorhynchus antennarius could not be found in any major European institution and is considered lost. No specific type locality is given; just “Grosses Ocean” (the Pacific).
Type material of synonyms. Type material of Simorhynchus lilljeborgi could not be found in the NRS or NHMD and is considered lost. However, the NRS has one, partly dissected, juvenile male (1632), labelled “ Guinea Cukten on Rolas R. Graeff”, that may represent type material. No precise type locality is given; just “tropical parts of Atlantic”. The figures of this species provided by Bovallius (1890) confirm the synonymy.
Type material of Simorhynchotus stebbingi would be the same as Stebbing’s (1888) specimen of S. antennarius because Bovallius was just proposing a new name for Stebbing’s specimen which he believed to be different from S. antennarius of Claus (1871). The type locality is the tropical Atlantic, off Africa [11°05’N 18°15’W].
Material examined. In NHMD: numerous specimens from the Dana and Thor expeditions, and others, too many to list here, from all the World’s Oceans including the Mediterranean Sea. In SAM and SAMA (part): Meiring Naude collections from S.W. Indian Ocean, off South Africa, between Kosi Bay and just S. of East London, 216 females, 111 males (88 lots), mostly 0–212 m, few 0– 360 m. In SAMA: Coral Sea, Great Barrier Reef, north-east of Townsville, 9 females, 5 males (11 lots), C12653–63. S.W. Pacific, Tasman Sea, off central eastern Australia [about 31° – 35°S], 4 females, 4 males (6 lots), C5300–5. Bass Strait, Erith Island, 1 male, C12651. N.E. Indian Ocean, off northern Western Australia, Ningaloo Reef and Dampier Archipelago region, numerous males (6 lots, night light trap), C12645–50. S.W. Atlantic, off Brazil [24°38’S 45°25’W], 6 females, 7 males, C12603. N.W. Pacific, off Taiwan [21°01’N 123°E], 1 male, C12664; off Ryukyu Islands, Japan, 1 juvenile, C12665. N.E. Pacific, off California [33°02’N 122°03’W], 1 male, C12602. In USNM: N.W. Atlantic, from the Caribbean Sea in the south, north to Georges Bank off Massachusetts, 8 females, 8 males (12 lots), 108147, 224033, 1154666, 1154691, 1242790, 1243533, 1243537–43. S.W. Atlantic, off Brazil, off Sao Paulo & Rio Grande Norte, 1 female, 4 males (2 lots), 1243536, 1246988. N.E. Pacific, off Central America, 5 females, 2 males (3 lots), 108412, 1243532, 1243535. N. Pacific, near Marshall Islands, 3 males, 1243544; Hawaii, 1 male, 1243552. S.E. Pacific, off Peru [04°21’S 81°59’W], 1 female, 1243545. N.W. Pacific, Japan and Philippines region, 5 females, 20 males (7 lots), 1242803, 1243534, 1243546–51. Arabian Sea [27°10’N 49°51’E], 1 female, 106436.
Diagnosis. Body length up to 7.0 mm, but ovigerous females of about 4.0 mm have been noted. Head of females rounded, length about 0.6 x depth, as long as first 4 pereonites combined. Head of males slightly pointed, almost as long as deep, as long as first 5 pereonites combined. Buccal mass relatively small, protruding slightly below head. G1 relatively slender, simple; basis relatively narrow, slightly longer than remaining articles combined, with slight medial bulge on anterior margin in males; carpus with few setae and slight medial bulge on posterior margin; propodus much narrower than preceding articles. G2 marginally longer than G1; also relatively slender except for sub-chelate carpus; basis like that of G1; carpus almost as wide distally as propodus is long, with rounded postero-distal corner, armed with few strong setae on posterior margin. P3–6 with relatively slender dactylus of moderate length, those of P4 about 0.3–0.4 x propodus. P3 and P4 morphologically similar, P4 slightly longer than P3; merus slightly inflated anteriorly, sub-equal in length to carpus, slightly shorter than propodus, slightly shorter than 0.5 x basis. P5 distinctly the longest pereopod, about 1.3 x P4 and 1.2 x P6; basis rectangular/oval, length 1.8–2.0 x maximum width, with few long setae on anterior margin; merus sub-equal in length to carpus, about 0.7 x propodus, about 0.6 x basis. P6 basis broader than for P5 but almost equal in length, much broader proximally in males with length 1.4 x maximum width (1.5 x in females); merus length 0.8 x propodus, about 0.5 x basis; carpus length about 0.5 x propodus; anterior margin of carpus and propodus, and sometimes also antero-distal corner of merus, slightly serrated. P7 basis with bulging posterior margin, more prominent in males, length about 2.0 x maximum width in males (about 2.2 x in females), length about 0.8 x basis of P6 for both sexes; length of remaining articles about 0.5 x basis; propodus with antero-distal corner produced into rounded lobe; dactylus sharp, hook-like. U1 with articulated rami; exopod marginally longer than peduncle, about 0.8 x endopod. U2 and U3; endopod fused with peduncle; exopod slightly shorter than peduncle, about 0.5 x length endopod. Telson slightly longer than width at base, slightly more narrowed distally in males.
Remarks. Simorhynchotus antennarius is a relatively distinctive species, easily distinguished by the morphology of the gnathopods and urosome. The gelatinous associates are listed above.
Distribution. A relatively common and widespread species, found mainly in tropical regions of all the world’s oceans, including the Mediterranean Sea. It seems to prefer near-surface waters.
description: Published as part of Zeidler, Wolfgang, 2021, Review of the hyperiidean amphipod family Lycaeidae Claus, 1879 (Crustacea: Amphipoda: Hyperiidea), pp. 1-59 in Zootaxa 5081 (1) on pages 47-51, DOI: 10.11646/zootaxa.5081.1.1, http://zenodo.org/record/5769323