Lycaea pulex Marion 1874

Lycaea pulex Marion, 1874

(Figs 16–17)

Lycaea pulex Marion, 1874: 13–19, pl. 2, fig. 2.— Bovallius 1887: 32.— Stebbing 1888: 1567.— Chevreux 1900: 156–157.— Spandl 1924: 30, fig. 5.—Chevreux & Fage 1925: 429–430, fig. 419.— Stephensen 1925: 167–168, 230 (tab.).— Chevreux 1927: 140.— Pirlot 1930: 24–25.— Barnard 1937: 190.— Pirlot 1939a: 45.— Shoemaker 1945: 243.— Shoemaker 1948: 14.— Bulycheva 1955: 1048 (tab.).— Hurley 1955: 180 (key).— Reid 1955: 25.—Hurley 1956: 20–21.— Irie 1957: 10 (incl. tab.).— Pillai 1957: 62–63, fig. xvii, 4–8.— Irie 1959: Table 4, 32 (tab.).— Hurley 1960: 282, 284 (tab.).— Pillai 1966b: 224–225, fig. 14.—Hure et al. 1969: 603, 605 (tabs.).— Dick 1970: 67, fig. 12 (part).— Yoo 1971: 43 (list), 63.— Tashiro & Jossi 1972: fig. 8 (map), 20 (list), 33 (tab.).—Harbison 1976: 153–160, figs 2–11.— Harbison & Madin 1976: 167–169, figs 1B, 3C, 4E.— Madin & Harbison 1977: 453 (tab.), 455–456, fig. 4.— Laval 1980: 19, 20, 23 (tabs.).— Brusca 1981: 44.— Vinogradov et al. 1982 /1996: 382/472 (key), 382–384/472–474, fig. 205 (part).— Macquart-Moulin 1993: 1158 (tab.), 1164, fig. 12 (distribution, part).— Lin & Chen 1994: 118 (list).— Shih & Chen 1995: 171 (key), 171–173, figs 110–111.— Lin et al. 1996: 230 (tab.).— Vinogradov & Semenova 1996: 615.— Zeidler 1998: 104, figs 60–61.— Barkhatov et al. 1999: 808 (tab.).— Vinogradov 1999: 1147 (tab.), 1194 (key), 1194–1195, fig. 4.140.— 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.).— Gates et al. 2003: 320 (text fig.), 321–322.— Gasca & Suárez-Morales 2004: 26 (tab.).— Brusca & Hendrickx 2005: 151 (list).— Zelickman 2005: xvii (list), fig. 38a-d (pp. 234–241).— Garcia-Madrigal 2007: 156, 192 (list).— Gasca 2007: 119 (tab.).— Gasca & Franco-Gordo 2008: 569 (tab.), 571–572.— Gasca 2009a: 89 (tab.), 91.— Gasca 2009b: 66 (tab.).— Gasca et al. 2009: 1497 (tab.).— Lavaniegos & Hereu 2009: passim.— LeCroy et al. 2009: 969 (tab.).—Gasca et al. 2012: passim.— Valencia & Giraldo 2012: 1492 (tab.), 1497.— Valencia et al. 2013: 51 (tab.).—Gasca & Franco- Gordo 2014: 75 (list).— Lavaniegos 2014: passim.— Zhang et al. 2014: 216.— Burridge et al. 2016: passim, table 2, fig. 1 (part).— Espinosa-Leal & Lavaniegos 2016: passim.— Zeidler 2016: figs 18–20 (pp. 50–52).— Gasca & Browne 2017: 3 (tab.), 6.— Lavaniegos 2020: 17 (tab.), passim.— Espinosa-Leal et al. 2021a: passim.

Lycaea robusta Claus, 1879: 186 (40).— Carus 1885: 426.— Bovallius 1887: 32.— Claus 1887: 63, pl. 19, figs 2–10.— Norman 1900: 134.— Lo Bianco 1902: 425 (list), 448.— Lo Bianco 1904: 44, pl. 23, fig. 76.—Harbison 1976: 162.— Harbison & Madin 1976: 169.— Laval 1980: 19 (tab.).

Lycaea similis Claus, 1879: 185 (39).— Bovallius 1887: 32.— Claus 1887: 63, pl. 18, figs 8–14.— Walker 1909: 54.— Pirlot 1929: 138.— Harbison & Madin 1976: 169.

Lycaea pauli Stebbing, 1888: 1566–1567.— Barnard 1930: 430, fig. 58.— Hurley 1955: 180 (key).— Harbison & Madin 1976: 169.— Vinogradov et al. 1982 /1996: 382/472 (key), 385/474–475, fig. 206.— Barkhatov & Vinogradov 1988: 167, 168 (tab.).— Vinogradov 1990: 74, 94 (tab.).— Vinogradov 1991: 261 (tab.).— Vinogradov 1993: 45 (tab.).— Barkhatov et al. 1999: 808 (tab.).— Gasca & Shih 2001: 496 (tab.).— Escobar-Briones et al. 2002: 367 (list).— Zelickman 2005: xvii (list), fig. 39a-d (pp. 242–249).— Gasca 2009a: 89 (tab.).— Gasca 2009b: 66 (tab.).— Lavaniegos & Hereu 2009: passim.— Zeidler & De Broyer 2009: 12, 66.— Valencia et al. 2013: 51 (tab.).— Lavaniegos 2014: 5 (tab.), fig. 5 (dendrogram).—Espinosa- Leal & Lavaniegos 2016: 150 (tab.).— Espinosa-Leal et al. 2021a: passim.

Type material. Type material of Lycaea pulex could not be found in any major European institution and is considered lost. The type locality is the Mediterranean Sea, Gulf of Marseille. Despite the apparent loss of the type material, this is a relatively well known species, readily characterised by the description and figures provided by Marion (1874).

Type material of synonyms. Type material of Lycaea robusta could not be found in any major European institution and is considered lost. The type locality is the Mediterranean Sea, off Naples and Messina. Claus’s (1887) illustrations of this species, especially of the male A1 and G1 and G2, confirm the synonymy, although the peduncle of U1 is illustrated as relatively long.

Type material of Lycaea similis could not be found in any major European institution and is considered lost. The type locality is the tropical W. Atlantic, off Lagos. Claus’s (1887) illustrations of this species, especially of G1 and G2, the relatively short dactyls and U1, confirm the synonymy.

The unique holotype male (7.6 mm) of L. pauli is in the NHM, London (89.5.15.248); on one microscope slide. The condition of the material is very poor and it is difficult to determine the species with certainty, but it is considered a synonym of L. pulex based on the short dactyls, the strongly sub-chelate G1 and G2 and the relatively shorter peduncle of U1. The type locality is the mid-Atlantic Ocean, off St. Paul’s Rocks [01°10’N 28°23’W], Challenger stn. 108, surface, 27 August 1873.

Material examined. The holotype male of Lycaea pauli as detailed above and the following. In NHMD: tropical Atlantic near Bahamas and southern central, Dana stn. 1243 iii (228142), 1 female; Dana stn. 1165 iii (228241), 1 female. N.E. Atlantic, 8 females, 2 males, Thor stns 377, 399, 400. Mediterranean Sea, 9 females, 2 males (6 lots), Thor stns 10, 160-3, 186, 216. Central S. Pacific, Dana stns 3585 xi, 3587 viii (228160, 619244), 2 females. E. Indian Ocean, off Sumatra, Dana stn. 3817 iv (228174), 1 female. S. of Japan, Jutlandia stn. 4775 (228237), 2 females. In SAM and SAMA (part): Meiring Naude collections from S.W. Indian Ocean, off South Africa, between Kosi Bay and just south of East London, 11 females, 8 males (14 lots), 250– 45 m. In SAMA: S.W. Pacific, Tasman Sea, off central eastern Australia to eastern Tasmania [about 33° – 44°S], 16 females, 5 males (12 lots), C5274–82 (excl. 77) and C12578–81, 250–0 m. S. Australia, Pearson Island, 1 female, C12582. S.W. Atlantic, off Brazil [23°28’S 41°57’W], 5 females, 3 males, C12583. N.E. Pacific, region off BC Canada, 19 females 17 males (10 lots), C12584–94 (excl. 92); off San Francisco, 1 female, C12595. In USNM: N.W. Atlantic, from French Guiana in the south, north to Georges Bank, off Massachusetts, 17 females, 9 males (19 lots), 12873, 264108, 1178034, 1241232, 1241237, 1241243–4, 1241285, 1241287–8, 1242772, 1242786, extracted from 1242794, 1242808, 1246971, 1246976, 1246991, 1253862, 1277467. S.W. Atlantic, off Brazil, 6 females, 2 males, 10 juveniles (4 lots), 1246965, 1246982–3, 1247117. N.E. Pacific, off Central America, 1 female, 3 males (3 lots), 1242802, 1247124, 1253890. S.E. Pacific, off Chile [22°54’S 77°10’W], 1 female, 1246962; near Galapagos Islands [00°02’S 96°02’W], 75 males (night light), 1247123. Japan, Kyushu Island [31°19’N 132°11’30”E], 6 males, extracted from 1242796.

Diagnosis. Body length up to 9.0 mm. Head of females relatively large, deeper than long, as long as first 4 pereonites combined. Head of males more rounded, slightly deeper than long, as long as first 3.5 pereonites combined. Buccal mass protruded well below head. Callynophore of A1 of males without antero-distal corner; postero-distal corner small, rounded, partly over-lapping following article. G1 and G2 sub-chelate, morphologically similar, G2 slightly longer than G1; basis of G1 slightly broader and shorter than G2; carpus rectangular with sharp postero-distal tooth, reaching just past base of dactylus, especially in males; propodus with postero-distal corner produced posteriorly to dactylus; carpus and propodus with small serrations on distal margin; dactylus slender, length about 0.5 x propodus. P3–6 with relatively short, stubby dactylus, those of P3 and P4 only about 0.2 x propodus. P3 and P4 morphologically similar, P4 slightly longer than P3; merus slightly inflated anteriorly, sub-equal in length to propodus, about 0.5 x length basis; carpus length about 0.8–0.9 x propodus. P5 only slightly longer than P4 or P6; basis rectangular/oval, length 1.5–1.7 x maximum width; merus marginally inflated anteriorly, sub-equal in length to propodus, about 0.6 x basis; carpus length about 0.7–0.8 x propodus. P6 basis length 1.5–1.7 x maximum width, more oval-shaped than P5 but equal in length; merus, carpus and propodus similar in relative lengths to P5; anterior margin of carpus and propodus, and antero-distal corner of merus, slightly serrated. P7 basis with bulging posterior margin, length about 1.5 x maximum width, about 0.8 x basis of P6; length of remaining articles slightly shorter than 0.5 x basis; propodus without antero-distal corner produced into rounded lobe; dactylus sharp, hook-like. U1 and U2; endopod not fused with peduncle. U1 peduncle length about 2.0 x exopod or slightly less; rami relatively slender, equal in length. Telson length about 1.5 x width at base.

Remarks. Lycaea pulex is one of the larger species of Lycaea reaching maturity at about 9.0 mm or slightly less. It is best distinguished from its congeners by the relatively short peduncle of U1 (about 2.0 x length exopod) and the very short dactylus of P3–6. Amongst the ‘short dactylus’ group it is readily distinguished by the morphology of G1 and G2 alone; the relatively shorter peduncle of U1 also distinguishes it from the remaining two congeners, L. bovallii and L. vincentii. Harbison (1976) gives a more detailed account of this species. Many of the species of Lycaea recognised by Harbison & Madin (1976) have, at times, been confused with this species. Most of this confusion is because of the poor descriptions and illustrations, generally, of species in the literature. Also, Vinogradov et al. (1982, 1996), in their illustration of L. pulex, borrow the figure of the habitus and male antenna from Stebbing’s (1888) illustration of L. vincentii that they regard a synonym but which is now considered a valid species. Hence, some of the species listed in the literature as Lycaea pulex, in the above list, may be mis-identifications.

Of note is one relatively large (7.6 mm) female specimen from the central mid-Atlantic (NHMD-228241), with a very large head, almost as long as the pereon. Apart from the head it is like other specimens of L. pulex and has been determined as such for the time being.

It has been recorded in association with a variety of salps, Cyclosalpa pinnata, Pegea confoederata (Harbison 1976); Cyclosalpa affinis, C. bakeri, C. pinnata, Helicosalpa komaii (Ihle & Ihle-Landenberg, 1936), Ihlea punctata (Forsskål, 1775), Pegea socia, P. bicaudata (Quoy & Gaimard, 1826), P. confoederata, Salpa cylindrica, S. maxima and Traustedtia multitentaculata (Quoy & Gaimard, 1834) (Madin & Harbison 1977). And, like L. pachypoda, it has also been recorded from Salpa maxima and pyrosomes (Chevreux 1892, 1900; Chevreux & Fage 1925; Laval 1980). However, because of the confusion of this species with others in the past, it is likely that some of these associations refer to other species of Lycaea.

Distribution. This is one of the most commonly recorded species of Lycaea but determining its distribution precisely from the literature is problematical because of the past confusion with other congeners. However, it seems to be relatively common and widespread in tropical and warm-temperate regions of all the world’s oceans, including the Mediterranean Sea. Most records are from the 0–500 m layer but it seems to prefer near-surface waters.