Lycaeopsis themistoides Claus

Zeidler, Wolfgang, 2004, A review of the hyperiidean amphipod superfamily Lycaeopsoidea Bowman & Gruner, 1973 (Crustacea: Amphipoda: Hyperiidea), Zootaxa 520, pp. 1-18 : 6-10

Lycaeopsis themistoides Claus ( Figs 1­4 )

? Phorcus reynaudii Milne Edwards, 1830: 392 . Milne Edwards 1838: 304. Milne Edwards 1840: 79 (“ raynaudii ”). Lucas 1840: 235. Bate 1862: 339 –340, pl. 53, fig. 9 (“ raynaudii ”). Bovallius 1887: 28 (“ reynaudi ”). Claus 1887: 66 (“ raynaudii ”).

? Phorcus hyalocephalus Dana, 1853: 1006 –1008, pl. 69, fig. 2a–c. Bate 1862: 340, pl. 53, fig. 10. Bovallius 1887: 29. Claus 1887: 66.

Lycaeopsis themistoides Claus, 1879: 42 (188). Carus 1885: 426. Bovallius 1887: 29. Claus 1887: 67, pl. 19, figs 11–24. Chevreux 1913: 16 –22, figs 6–8. Chevreux & Fage 1925: 417 –418, fig. 412. Stephensen 1925: 153 –155. Spandl 1927: 213 –214, fig. 35. Pirlot 1929: 142 –143. Pirlot 1930: 27 –28, fig. 8. Barnard 1930: 425 –426. Barnard 1931: 128. Chevreux 1935: 192 –195, pl. 13, fig. 9, pl. 14, fig. 3, 7. Pirlot 1939: 42 –43. Hurley 1955: 179. Reid 1955: 23. Irie 1959: table 4, 32 (table). Evans 1961: 201. Grice & Hart 1962: 300. Kane 1962: 310. Vinogradov 1962: 23. Siegfried 1963: 9. Laval 1965: 6198. Dick 1970: 64, fig. 10 (part). Yoo 1971: 59 –60. Thurston 1976: 432 –433. Harbison et al. 1977: 470. Shulenberger 1977: 379 (table). Tranter 1977: 648 (table), 650. Zeidler 1978: 20 –21 (part). Laval 1980: 19 (table), 20. Brusca 1981: 30 (key), 43, fig. 16a–d. Stuck et al. 1980: 365. Vinogradov et al. 1982: 358 –359, fig. 192, Lin & Chen 1988: 328. Vinogradov 1990: 71. Vinogradov 1991: 261 (table). Lin & Chen 1994: 118 (list). Montu 1994: 132 (list). Lin et al. 1995: 122 (table). Shih & Chen 1995: 140 –143, figs 88, 89. Lin et al. 1996: 230 (table). Zeidler 1998: 70, fig. 39B, C. Vinogradov 1999: 1192, fig. 4.132. Gasca & Shih 2001: 496 (table). Lima & Valentin 2001: 473 (list), 475 (table). Gasca & Suarez­Moráles 2004: 26 (table)

? Phorcus loveni Bovallius, 1887: 29 .

Phorcorrhaphis edwardsi Stebbing, 1888: 1455 –1458, pl. 181. Stebbing 1910: 656.

Lycaeopsis edwardsi Spandl 1924: 28 –30, fig. 4.

Type material

Type material of L. themistoides could not be found at the ZMB or ZMH and is considered lost. However, the description and figures provided by Claus (1879, 1887) are sufficient to characterise this species. The type locality is Messina Harbour, Mediterranean Sea.

Type material of synonyms

Despite the loss of type material of P. reynaudii , it is considered a likely synonym of L. themistoides , rather than L. zamboangae , because Milne Edwards’s (1830) description refers to a male, but he makes no mention of the peculiar endopod of uropod 3, or the telson, which characterise L. zamboangae . Likewise, Bate (1862) describes and illustrates a male, from material that he believed to be types, without mentioning the obvious characteristics of L. zamboangae .

Type material of P. hyalocephalus could not be found at the USNM, or in any other major North American museum, and is considered lost. It is considered a likely synonym of L. themistoides for the same reason as P. reynaudii .

Type material of P. l o v e n i could not be found at the SMNH, ZMUC or in Uppsala and is considered lost. It is a likely synonym of L. themistoides based on Bovallius’s (1887) brief description. However, in the SMNH are two lots of specimens labelled “ Phorcus ”. One of these ( SMNH 1678) is from the mid­Atlantic and consists of a mixture of both species. The other one ( SMNH 1679) is labelled “Caraibiska Sjon 17º58N 67º33W Balders Exp. No. 141” and may represent type material. It consists of two males, both of which are clearly L. zamboangae .

Two syntype males of P. e d w a rd s i are in the BMNH (89.5.15.247). Both specimens are readily identifiable with L. themistoides . Because of the extreme sexual dimorphism, Stebbing (1888) did not appreciate that his species was merely the male of L. themistoides , the original description of which was based on a female.

Material examined

Types. Two syntype males of Phorcorrhaphis edwardsi from the North Pacific, 24º49N 138º34E, surface, Challenger, 3 April, 1875: one in spirit, the other on three microscope slides.

Other material examined. Tasman Sea: 14 lots ( SAMA), 18 specimens. Coral Sea: 1 lot ( BMNH), 3 specimens. North Atlantic: 2 lots ( BMNH), 19 lots ( CMN), 11 lots ( USNM), 2 lots ( ZMB), 4 lots ( ZMUC), numerous specimens. South Pacific: 2 lots ( BMNH), 2 specimens. Philippines: 2 lots ( USNM), 2 specimens. Indian: 1 lot ( BMNH), several lots ( SAM), numerous specimens. Mediterranean: 1 lot ( ZMH), 34 lots ( ZMUC), numerous specimens.

Diagnosis

Head oval in vertical plane. Antennae 1 of female with peduncle of three articles (total 5 articles). Antennae 2 of male about half as long as mandibular palp. Pereopod 6 of male; basis sometimes with slightly concave posterior margin; merus with relatively evenly convex posterior margin. Pereopod 6 of female with merus shorter than carpus. Uropod 2; exopod reaches slightly beyond peduncle of U3. Uropod 3; peduncle length is about half­length of exopod. Telson slightly exceeds peduncle of U 3 in length.

Remarks

Morphologically this species is very similar to its only congener, L. zamboangae . It is most readily distinguished by the key and the diagnosis given above, especially the males. The best characters to distinguish females are the number of articles of the first antennae, the longer carpus and propodus of pereopod 6, the relative length of the double urosomite, and the telson length. Other useful characters are the larger and more rounded head ( Fig. 3 ), and the more coarsely toothed rami of the uropods. It is also interesting to note that, for males of similar size, the mandibular palp is about twice as long in L. themistoides than in L. zamboangae . The second antennae, which are of similar length, are about 0.7x the length of the mandibular palp in L. themistoides but slightly longer than the mandibular palp in L. zamboangae (compare figs 1 & 3).

Lycaeopsis themistoides has been recorded as living in diphyid siphonophores. Stephensen (1925) recorded two specimens in Diphyes ; Harbison et al. (1977) found it in the superior nectophore of Diphyes dispar , and Laval (1965) found it in the anterior nectophore of Chelophyes appendiculata .

Distribution

This is an uncommon, but widely distributed species, in tropical and temperate regions, usually found in surface waters. It is also relatively common in collections from off the southeastern coast of South Africa.

Figures

FIGURE 1. Lycaeopsis themistoides, male 4.4 mm, Tasman Sea, SAMA C 5098 (m); ovigerous female 3.1 mm, Indian Ocean, off South Africa, SAMA C 5830 (f). A, lateral view of male. Scale bars = 0.5 mm (A 1 & 2 ­ m), 0.05 mm (remainder).

FIGURE 2. Lycaeopsis themistoides, male 4.4 mm, Tasman Sea, SAMA C 5098. Scale bar = 0.2 mm.

FIGURE 3. Lycaeopsis, Indian Ocean, off South Africa, SAMA C 5830 (A), C 5829 (B – K). A, L. themistoides, female 3.1 mm, A 1; B – D, L. zamboangae, female 3.3 mm, A 1, A 2, Md; E­G, L. zamboangae, male 4.3 mm, Md, A 2, Mxp; H, I, L. zamboangae, head female 3.2 mm, head male 3.7 mm; J, K, L. themistoides, head female 2.8 mm, head male 3.4 mm. Scale bars = 0.5 mm (H­K), 0.05 mm (A – G).

FIGURE 4. Lycaeopsis, Tasman Sea, SAMA C 5096 (A), C 5098 (B), C 5101 (D); Indian Ocean, off South Africa, SAMA C 5829 (C). A, B, urosomes of L. themistoides, female 3.3 mm, male 4.4 mm; C, D, urosomes of L. zamboangae, female 3.2 mm, male 3.4 mm. Scale bar = 0.2 mm.