Byblis pialba, Poore & Lowry, 2023

Poore, Gary C. B. & Lowry, James K., 2023, New Australian Species of Ampeliscidae (Crustacea: Amphipoda) from the Great Barrier Reef and Eastern Australia with a Key to Australian Species, Records of the Australian Museum (Rec. Aust. Mus.) 75 (4), pp. 519-533 : 529-530

Byblis pialba sp. nov.

urn:lsid:zoobank.org:act:73E30020-B5C5-4BAA-A9FD-25A807520B4F

Figs 7 , 8

Holotype: AM P.85989, female, tl. = 5.7 mm (with 4 microslides; 1 missing), Australia, Queensland, Lizard Island , fringing reef between Bird Islet and South Island, 14°40'S 145°28'E, Halophila , mixed algae and sediment from grass beds off reef base, 24.4–37.6 m, P. C. Terrill, 9 Oct 1978.

Description of holotype. Head. Head 1.7 times as long as deep; rostrum minute; anteroventral margin strongly concave; eyes present, with 2 pairs with cuticular lenses. Antenna 1 peduncular article 2 2.5 times length of article 1; flagellum of 11 articles; almost reaching end of peduncle of antenna 2. Antenna 2 about as long as body length; peduncular article 5 as long as article 4. Mandible palp article 2 tapering distally.

Pereon. Coxae 1–3 with denticulate lower margin (less obvious on third). Gnathopod 1 coxa anterior margin slightly concave, anteroventral corner broadly convex. Pereopods 3, 4 dactylus shorter than propodus. Pereopod 5 basis flexor margin with prominent proximal lobe; extensor margin without plumose setae. Pereopod 6 basis subcircular, extensor margin with 8 plumose setae. Pereopod 7 basis posterodistal margin broadly rounded, reaching to distal margin of merus, free anterior margin setose near junction with ischium; merus slightly longer than wide; carpus 1.5 times as long as wide, as long as ischium-merus together; propodus linear, 2.5 times as long as wide.

Pleon. Epimeron 3 posteroventral margin broadly rounded. Uropod 1 rami with 2 short robust setae each. Uropod 2 inner ramus inner ramus shorter than outer ramus, upper margin with 4 robust setae. Uropod 3 rami margin of inner ramus serrate over distal two-thirds, margin of outer ramus serrate over middle third. Telson 1.3 times as long as wide, cleft over posterior 40%, with 3 pairs of submarginal setae; distal margin truncate, minutely serrulate.

Distribution. Australia, Queensland, northern Great Barrier Reef, reef sediment, 24–38 m (known only from type locality).

Remarks. Byblis pialba is the only species of the genus in Australia with antenna 2 about as long as the body length. Byblis brachyura Ren, 2006 , B. longiflagella Ren, 2006 , B. orientalis J. L. Barnard, 1967 and B. pirloti Margulis, 1968 are the only species among the 29 figured by Ren (2006) with a long antenna 2.

Figures

Figure 7. Byblis pialba sp. nov., holotype, female, 5.7 mm, AM P.85989.

Figure 8. Byblis pialba sp. nov., holotype, female, 5.7 mm, AM P.85989.