Ichnopus capricornus Lowry & Stoddart, 1992

Lowry, J. K. & Stoddart, H. E., 2009, Uristidae *, Zootaxa 2260 (1), pp. 908-918 : 909-911

Ichnopus capricornus Lowry & Stoddart, 1992

( Figs 1 , 2 )

Ichnopus capricornus Lowry & Stoddart, 1992: 198 , figs 6–8. –– Springthorpe & Lowry, 1994: 12. –– Keable, 1995: 33, 42. –– Lowry & Stoddart, 2003: 281 (catalogue).

Type locality. Boulder ridge on north side of Heron Island, Great Barrier Reef, Queensland, Australia (23°26'S 151°55'E) .

Material examined. That of Lowry & Stoddart (1992) and 2 specimens, AM P80139 (QLD311); 4 specimens, AM P80140 (QLD 325); many specimens, AM P80141 (QLD 342); 1 specimen, AM P80142 (QLD 374); 11 specimens, AM P80143 (QLD 379); 3 specimens, AM P80144 (QLD 396); many specimens, AM P80145 (QLD 401); many specimens, AM P80146 (QLD 427); many specimens, AM P80147 (QLD 429); many specimens, AM P80148 (QLD 454); many specimens, AM P80149 (QLD 455); 1 specimen, AM P80150 (QLD 481); 1 specimen, AM P80151 (QLD 547); 4 specimens, AM P80152 and many specimens, AM P80153 (QLD 548); many specimens, AM P80154 (QLD 574); several specimens, AM P80155 (QLD 575); many specimens, AM P80156 (QLD 577); 3 specimens, AM P78946 (QLD 635); several specimens, AM P78947 (QLD 652); several specimens, AM P78948 (QLD 653); several specimens, AM P78949 (QLD 654); several specimens, AM P78950 (QLD 655); many specimens, AM P78951 (QLD 656); several specimens, AM P78952 (QLD 670); 4 specimens, AM P78953 (QLD 671); many specimens, AM P78954 (QLD 673) ;

Description. Based on holotype female, 10 mm, AM P39644.

Head. Head lateral cephalic lobes rounded, with apically rounded margins; eyes reniform. Antenna 1 shorter than antenna 2; peduncle article 1 with short posterodistal spine; articles 2 and 3 short; flagellum with strong 2-field callynophore, robust setae absent from proximal articles, calceoli absent; accessory flagellum with 6 articles. Antenna 2 less than 40% of body length; peduncle with strong brush setae; calceoli absent. Epistome / upper lip separate; upper lip produced, rounded apically. Mandible molar setose tongue with conate setae; palp attached midway, article 3 without A3-setae. Maxilla 1 outer plate with setal-teeth in 7/4 crown arrangement; setal-tooth 7, left and right symmetrical, cuspidate distally; palp distal margin with apical robust setae and serrations. Maxilliped inner plates poorly developed, not reaching half the length of the outer plate; outer plates without apical robust setae; palp 4-articulate, article 4 well developed.

Pereon. Gnathopod 1 simple; coxa large, about as long as coxa 2, subrectangular with concave anterior margin; basis slightly expanded proximally, sparsely setose along anterior margin; ischium elongate, more than twice as long as broad; carpus very long (length 4 x breadth), distinctly longer than propodus, without posterior lobe; propodus margins subparallel, sparsely setose along posterior margin; dactylus complex, with large subapical spine, row of medial robust setae and row of long cuticular spines along posterior margin. Gnathopod 2 minutely subchelate; carpus 2.3 x as long as propodus; palm transverse, slightly concave; dactylus minute. Pereopod 4 coxa with well developed posteroventral lobe. Pereopod 5 coxa equilobate; basis about as long as broad, posterior margin strongly serrated.

Pleon. Epimeron 3 posterior margin smooth, posterodistal corner acutely produced with tiny basal notch. Urosomite 1 with shallow dorsal depression, dorsally straight. Uropod 1 rami subequal. Uropod 2 rami subequal, inner ramus with weak marginal constriction. Uropod 3 stout; peduncle without dorsolateral flange; rami subequal, with long fine setae on each ramus; plumose setae absent; outer ramus 2-articulate, article 2 short, inner ramus extending beyond article 1 of outer ramus. Telson distinctly longer than broad, deeply cleft, without dorsal robust setae, with 1 apical robust seta per lobe.

Male (sexually dimorphic characters). Based on paratype male, 9.8 mm, AM P39645. Antennae 1 – 2 with calceoli .

Habitat. Scavenger living on coral and sandy patches between coral, from 0 to 30 m depth.

Remarks. Ichnopus capricornus apparently occurs throughout the GBR where it overlaps with I. tenuicornis . Both of these species can be separated from other lysianassoids on the GBR by the complex dactylus of gnathopod 1 and the strongly serrate posterior margin of pereopod 5 basis. They differ most noticeably from each other in the palm of the female second gnathopod, which is minute in I. capricornus and enlarged in I. tenuicornis , and in the proximal articles of antenna 1 which have large robust setae in I. tenuicornis (absent in I. capricornus ).

Distribution. Australia. Queensland: Lizard Island ( Lowry & Stoddart 1992; current study); Heron Island; ( Lowry & Stoddart 1992); Flynn Reef (current study).

Figures

FIGURE 1. Ichnopus capricornus Lowry & Stoddart, 1992, holotype, female, 10 mm, AM P39644, Heron Island, Great Barrier Reef (after Lowry & Stoddart, 1992).

FIGURE 2. Ichnopus capricornus Lowry & Stoddart, 1992, holotype, female, 10 mm, AM P39644, Heron Island, Great Barrier Reef (after Lowry & Stoddart, 1992).