Birubius casuarina, Taylor, 2009

Taylor, Joanne, 2009, Phoxocephalidae *, Zootaxa 2260 (1), pp. 800-827 : 807-810

Birubius casuarina sp. nov.

( Figs 5 , 6 , Pl. 5F)

Type material. Holotype female, 6.0 mm, AM P71222, Casuarina Beach, Lizard Island (14°40.38’S 145°26.69’E), fine sediment in grass beds, sandy bottom with rubble, algae & sparse seagrass, 1 m, S. LeCroy, 2 March 2005 ( QLD 1771 ) . Paratype: female, 5.5 mm, AM P77840 ( QLD 1771 ) ; 1 female, 4.0 mm, AM P54648 ( QLD 50 ) .

Type locality. Casuarina Beach, Lizard Island , Queensland, Australia .

Etymology. Named for the type locality Casuarina Beach, Lizard Island.

Description. Based on holotype female.

Head. Rostrum slightly/weakly constricted, broadly rounded distally. Eyes present (pigmented black in preserved specimens). Antenna 1 peduncle article 2 with ventral setae situated on middle. Antenna 2 peduncle article 4 facial robust setae not in a single row, dorsal setae present; article 5 midfacial robust setae present as a single set of 1–3; flagellum multiarticulate. Mandible palp article 2 without outer setae, molar simple, form D; right molar with 6 spines and 1 strongly disjunct short spine; right incisor with 3 teeth, right lacinia mobilis simple, right raker row of 7 teeth,. Maxilla 1 inner plate unknown; outer plate with 1 robust seta especially thickened. Maxilliped inner plate with 1 large thick apical robust seta; outer plates, inner margin with well developed setae.

Pereon. Coxae, long ventral setae present on coxae 1–3 but absent from coxa 4, main ventral setae of coxae 1–4 = 6–8–10–0. Coxa 1 weakly-scarcely expanded distally. Gnathopods similar. Gnathopod 1 palms oblique. Pereopods 3–4, carpus with 2 posteroproximal robust setae, propodus slender setae absent. Pereopod 5 basis not tapering distally, without facial ridge. Pereopod 6 basis with 1 facial ridge. Pereopod 7 basis with long ventral setae, with 2 facial ridges.

Pleon. Epimeron 1 anteroventral margin with 6 setae, posteroventral face with 2 long setae. Epimeron 2 with 9 facial setae, crowded anteriorly. Epimeron 3 facial setae absent, with 5 long posterior setae, with 5 ventral setae. Uropod 1, peduncle basofacial setae present, without major displaced robust setae, with 3–4 apicolateral spines; inner ramus with 1 dorsal spine, without subapical accessory robust seta; outer ramus not continuously spinose to apex. Uropods 1–2 rami with well developed apical nails. Uropod 3 outer ramus article 2 with 2 apical setae.

Habitat. Coarse-fine sediment in grass beds, sandy bottom with rubble, algae and sparse seagrass.

Remarks. This species is very close to Birubius jirrandus Barnard & Drummond, 1978 described from Western Port and Port Phillip Bay, Victoria and Barrow Island, Western Australia. Comparison of the Lizard Island material with the holotype confirmed differences warranting the erection of a new species. The material from Lizard Island lacks the distally expanded coxa 1 of B. jirrandus and has longer setae and more pronounced ventral serration on pereopod 7. The robust seta on the inner plate of the maxilliped is considerably more robust than B. jirrandus . The characters useful in distinguishing this species from other species of the genus from the GBR are pereopods 3–4 carpus with 2 posteroproximal robust setae; long ventral setae on pereopod 7 basis; the presence of basofacial setae on uropod 1. The eyes are pigmented black in preserved material which aids in distinguishing this species from the red pigmented eyes of B. batei . It can be distinguished from all species of the genus from the GBR by the presence of ventral and posterior setae, but lacks fully facial setae on epimeron 3.

Distribution. Australia. Queensland: Lizard Island (current study).

Figures

FIGURE 5. Birubius casuarina sp. nov., holotype, female, 6.0 mm, AM P71222, Casuarina Beach, Lizard Island, Great Barrier Reef.

FIGURE 6. Birubius casuarina sp. nov., holotype, female, 6.0 mm, AM P71222, Casuarina Beach, Lizard Island, Great Barrier Reef.