Ichnopus tenuicornis (Haswell, 1879)

Lowry, J. K. & Stoddart, H. E., 2009, Uristidae *, Zootaxa 2260 (1), pp. 908-918 : 912-914

Ichnopus tenuicornis (Haswell, 1879)

( Figs 3 , 4 )

Glycera tenuicornis Haswell, 1879a: 256 , pl. 8, fig. 6. –– Della Valle, 1893: 849. – Springthorpe & Lowry, 1994: 33.

Glycerina tenuicornis . –– Haswell, 1882: 234, pl. 4, fig. 6. –– Stebbing, 1906: 61. –– Barnard & Karaman, 1991: 488.

Ichnopus tenuicornis . –– Lowry & Stoddart, 1992: 230: figs 29–32. –– Keable, 1995: 42. –– Lowry & Stoddart, 2003: 282. not Glycera tenuicornis . –– Haswell, 1879b: 322.–– Whitelegge, 1889: 55.

not Glycerina tenuicornis . –– Pirlot, 1936: 271, figs 106, 107 (= I. wardi Lowry & Stoddart, 1992 ).––J.L. Barnard, 1974: 141.

Type locality. Howick Group , Great Barrier Reef, Queensland, Australia (~ 14°30'S 144°58'E) .

Material examined. That of Lowry & Stoddart (1992) and 1 specimen, AM P78957 (QLD 135) ; 2 specimens, AM P78958 (QLD 171) ; 3 specimens, AM P45406 (QLD 251) ; 2 specimens, AM P78959 (QLD 283) ; 1 specimen, AM P78960 (QLD 290) ; 8 specimens, AM P78963 (QLD 337) ; 1 specimen, AM P78965 (QLD 346) ; 1 specimen, AM P78969 (QLD 368); many specimens , AM P80129 (QLD 434) ; 3 specimens, AM P80130 (QLD 509) ; 4 specimens, AM P80132 (QLD 549) ; 6 specimens, AM P80134 (QLD 597); many specimens , AM P78955 (QLD 784); many specimens , AM P78956 (QLD 785) ; 2 specimens, AM P49504 (QLD 915) ; 27 specimens, AM P49507 (QLD 916) ; 13 specimens, AM P56936 (QLD 919) ; 304 specimens, AM P50205 (QLD 922) ; 633 specimens, AM P50216 (QLD 923) ; 4 specimens, AM P50250 (QLD 933) ; 7 specimens, AM P50254 (QLD 935) ; 1 specimen, AM P50372 (QLD 937) ; 7 specimens, AM P50376 (QLD 938) ; 295 specimens, AM P49511 and 14 specimens, AM P57608 (QLD 939) ; 560 specimens, AM P50271 (QLD 941) ; 25 specimens, AM P51115 (QLD 953) ; 1 specimen, AM P49528 (QLD 1033) ; 15 specimens, AM P49533 (QLD 1037) ; 175 specimens, AM P49534 (QLD 1039) ; 21 specimens, AM P50342 (QLD 1052) ; 52 specimens, AM P52251 (QLD 1054) ; 5 specimens, AM P49540 (QLD 1055) ; 60 specimens, AM P49543 (QLD 1059) ; 47 specimens, AM P49544 (QLD 1060) ; 50 specimens, AM P52265 (QLD 1195) ; 68 specimens, AM P52280 (QLD 1197) ; 84 specimens, AM P52434 (QLD 1213) ; 8 specimens, AM P57726 (QLD 1215) .

Description. Based on lectotype female, 10.5 mm, AM P39547.

Head. Head lateral cephalic lobes subtriangular, 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 present on proximal articles; calceoli absent; accessory flagellum with 4+ 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 a 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. 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, without setae along anterior margin; ischium elongate, more than twice as long as broad; carpus very long (length 5.7 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 subchelate; carpus twice as long as propodus; palm large, acute, concave; dactylus well developed. 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 above a small spine. Urosomite 1 with shallow dorsal depression, dorsally straight. Uropod 1 rami subequal. Uropod 2 rami subequal, inner ramus with moderate 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 paralectotype, male, 9 mm, AM P39548. Antennae 1–2 with calceoli. Antenna 2 slightly more than half length of body. Gnathopod 2 palm and dactylus minute .

Habitat. Scavenger living on coral and sandy patches between coral, 6 to 32 m depth.

Remarks. Ichnopus tenuicornis is a widespread scavenger in tropical Australia. It differs from other lysianassoids on the GBR as discussed in the remarks under I. capricornus .

Distribution. Australia. Queensland: Bet Reef (current study); Thursday Island (current study); Howick Group ( Haswell 1879a); Lizard Island ( Lowry & Stoddart 1992; current study); Flynn Reef (current study); Fitzroy Reef (current study); Mooloolaba (current study). Western Australia: North West Shelf ( Lowry & Stoddart 1992). Northern Territory: Oxley Island ( Lowry & Stoddart 1992).

Figures

FIGURE 3. Ichnopus tenuicornis Haswell, 1879, lectotype, female, 10.5 mm, AM P39547, Howick Group, Great Barrier Reef (after Lowry & Stoddart, 1992).

FIGURE 4. Ichnopus tenuicornis Haswell, 1879, lectotype, female, 10.5 mm, AM P39547, Howick Group, Great Barrier Reef (after Lowry & Stoddart, 1992).