Lycaeopsis themistoides Claus
- Dataset
- A review of the hyperiidean amphipod superfamily Lycaeopsoidea Bowman & Gruner, 1973 (Crustacea: Amphipoda: Hyperiidea)
- Rank
- SPECIES
Classification
- kingdom
- Animalia
- phylum
- Arthropoda
- class
- Malacostraca
- order
- Amphipoda
- family
- Lycaeopsidae
- genus
- Lycaeopsis
- species
- Lycaeopsis themistoides
diagnosis
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 U 3. Uropod 3; peduncle length is about halflength of exopod. Telson slightly exceeds peduncle of U 3 in length.
discussion
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 0.7 x the length of the mandibular palp in L. themistoides but slightly longer than the mandibular palp in L. zamboangae (compare figs 1 & 3).
distribution
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.
materials_examined
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 17 º 58 N 67 º 33 W 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, 24 º 49 N 138 º 34 E, 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.
Name
- Homonyms
- Lycaeopsis themistoides Claus