Cystisoma longipes (Bovallius)

Zeidler, Wolfgang, 2003, A review of the hyperiidean amphipod family Cystisomatidae Willemöes­Suhm, 1875 (Crustacea: Amphipoda: Hyperiidea), Zootaxa 141, pp. 1-43 : 14-19

Cystisoma longipes (Bovallius) ( Figs 4­6 )

Thaumatops longipes Bovallius, 1886: 13 ­16, figs 15­23. – Bovallius 1887a: 15. Bovallius 1889: 47 ­52, pl. 3, fig. 1­6 (spec. A, non B). Walker 1909: 50 (list), 52.

Cystisoma longipes – Chevreux 1935: 169. Vinogradov et al. 1982: 253 ­254, fig. 124. Vinogradov 1993: 42, 43 (Table). Vinogradov 1999: 1176, fig. 4.72.

Thaumatops bovallii Woltereck, 1903: 457 . – Stephensen 1918: 59 ­62, fig. 20. Schellenberg 1927: 621 ­622, fig. 30.

Cystisoma africanum Barnard, 1916: 287 ­289. – Dick 1970: 54.

Cystisoma magna [misidentification] – Shoemaker 1945: 233 ­234.

Type material

The unique type of C. longipes , measuring about 40 mm, is in the ZMUC ( CRU 2829). It appears to be a young female as the second pereonites have a small bud ventrally, representing the developing brood plates. The type locality is “off the west coast of Australia ”, 30ºS, 90ºE.

Type material of synonyms

The two female syntypes of C. bovallii could not be found at the ZMB or ZMH and are presumed lost. Woltereck’s (1903) description is very brief and there are no figures. The species is characterised by having a mandible with one central and one lateral tooth, and antennae slightly shorter than the head; characters which apply only to C. longipes . Woltereck (1903) probably failed to appreciate this synonymy because Bovallius (1886) wrongly stated that the first two pereonite segments of his species were not fused.

The unique type of C. africanum , a female measuring in excess of 90 mm, is in the BMNH (1933.1.25.902 – previously SAM A239). It is not a moult as suggested by Dick (1970). Despite being in several pieces there is not problem identifying it as C. longipes .

Material examined (78 specimens)

Types. Holotype female of Thaumatops longipes , approximately 40 mm: in spirit, damaged. Holotype female of C. africanum , approximately 90 mm, from the Indian Ocean, near South African coast, 33ºS, “Buffalo River (East London) N.W. by N. distant 21 miles, 490 fathoms. S.S. “Pieter Faure”. 22/4/01 ”: in several pieces in spirit.

Other material examined. North Atlantic: 8 lots ( USNM), 31 lots ( ZMUC), 56 specimens. South Atlantic: 2 lots ( SAM), 2 lots ( USNM), 1 lot ( ZMUC), 5 specimens. South Indian: 5 lots ( SAM), 1 lot ( SAMA), 4 lots ( ZMUC), 12 specimens. South Pacific: 3 lots ( ZMUC), 3 specimens.

Diagnosis

Body length of females up to 100 mm, of males up to 75 mm. Head almost as long as deep; about as long as first five pereonites combined; oval when viewed laterally, with evenly convex anterior margin when viewed dorsally. Marginal spines, 14­18; anterior ventral spine larger than glandular spine, clearly the largest; oral spines, 2­5 in arched row. Eyes oval, barely separated medially for anterior half, slightly wider apart posteriorly. First antennae as long as 0.7x length of head in immature specimens, but only about halflength head, or less, in mature specimens, with two small terminal articles. Mandibles with one medial tooth and at least one lateral tooth, very large specimens with 2­3 lateral teeth. Pereopods 5 & 6 with articles slightly more slender than in other species. Pereopod 5; carpus subequal in length to propodus. Urosome (with uropods) about as long as pleon. Uropod 1; exopod slightly longer than endopod (slightly shorter than endopod in juveniles), about 0.4x length of peduncle. Uropod 3 similar to U1, but exopod length slightly more than half­length of peduncle.

Remarks

This species is similar to C. magna in that mature specimens have relatively short first antennae. In all other species the first antennae are as long or much longer than the head. Juvenile specimens often have longer antennae, and amongst the material examined there are two specimens in which the first antennae are slightly longer than the head (SAM A42196, male 26 mm; SAM A42197, female ~ 35 mm). These two specimens may have been identified with C. latipes on the basis of antennal length but the shape of the head and pereopod articles are characteristic of C. longipes .

The shape of the eyes ( Fig. 6 ) also tend to resemble C. latipes more than other species because they are slightly more separated medially towards the posterior part of the head (e.g. SAM A42198, female 99 mm).

Cystisoma longipes is the only species in which there is more than one lateral mandibular tooth (in large specimens) ( Figs 4 , 6 ). In all other species, except for C. latipes , lateral mandibular teeth are absent.

As the name suggests the pereopods seem to be relatively longer than in other species. But this is because the articles, particularly of pereopods 5 and 6, are slightly more slender. There are no differences in the relative lengths of pereopods, or pereopod articles, when compared to other species.

The type of C. africanum ( Fig. 5) differs slightly from typical specimens in that the carpus of pereopod 6 is distinctly shorter than the propodus (as in C. pellucida ).

Figures

FIGURE 4. Cystisoma longipes, off Western Australia, ZMUC CRU 2829. Holotype female approx. 40 mm. Scale bars = 5.0 mm (G 1 ­ P 7), 0.5 mm (Md), 0.2 mm (Us).

FIGURE 6. Cystisoma longipes, mandibular teeth and eye shape. A, juvenile, 26 mm, North Atlantic, USNM; B, male, 75 mm, North Atlantic, USNM; C, male, 70 mm, Bermuda, USNM; D, female, 99 mm, Indian Ocean off South Africa, SAM A 42198; E, female, 55 mm, Southern Ocean, SAMA C 3826. Scale bars = 5.0 mm (D, E), 1.0 mm (B, C), 0.5 mm (A).