Cheirimedon cansada (Barnard, 1961)

Kilgallen, Niamh M., 2009, New species of lysianassoid Amphipoda (Crustacea) associated with seamounts, marine canyons and cold seeps of New Zealand, Zootaxa 2298 (1), pp. 1-30 : 10-12

Cheirimedon cansada (Barnard, 1961)

( Figure 7 )

Uristes cansada J.L. Barnard, 1961: 53 , fig. 21.

Uristes cansadus . — Barnard & Karaman, 1991: 539.

Cheirimedon cansada .— Lowry & Stoddart, 2003: 164.

Material examined. Holotype female, 7 mm, ZMUC CRU-5963 , Tasman Sea , 42º10’S, 170º10’E, 610 m

(Galathea Stn 627); 1 female, 5.5 mm, ZMUC CRU-20163 , also from type locality ; 1 male, 5.5 mm, NIWA 48673 , Paw Seep, Omakere Ridge, 40º03.17’S, 177º49.17’E, 1102 m (SO191-3/197), collected by TV-grab .

Distribution. New Zealand: Omakere Ridge, Hikurangi Margin; Tasman Sea. Australia: Tasman Sea (within 200 mile fishing zone); 610–1100 m.

Remarks. A single sub-adult male specimen was collected from Bear’s Paw Seep at the Omakere Ridge on the Hikurangi Margin. Comparison of this specimen with the female holotype revealed the following sexually dimorphic differences in the male: lateral cephalic lobes slightly narrower; antennae 1 and 2 with calceoli, antenna 2 longer, about 40% of body length; uropod 3 rami bearing long, slender setae, inner ramus extending past article 1 of outer ramus. Finally, the carina on urosomite 3 is also not as produced as in the female holotype, but, this is also the case for another female specimen (partially figured by Barnard 1961), and thus the degree of production of the carina is probably related to the maturity of the specimen. Only sexually dimorphic characters, as well as the mouthparts, which have not previously been illustrated, are figured here.

Figures

FIGURE 7. Cheirimedon cansada (Barnard, 1961), male, 5.5 mm, NIWA 48673: A, habitus; B, antenna 1; C, antenna 2; D, uropod 3; E, left mandible; F, maxilliped; G, maxilla 1; H, maxilla 2; I, right mandible. Scale bars, a = 2 mm (Figure 1A); b = 0.4 mm (Figures 7B, C); c = 0.2 mm (Figure 7D); d = 0.1 mm (Figures 7E–I).