Urohaustorius drummondae, Kilgallen, 2009

Kilgallen, Niamh M., 2009, Urohaustoriidae *, Zootaxa 2260 (1), pp. 919-926 : 922-923

Urohaustorius drummondae sp. nov.

( Figs 3–5 )

Type material. Holotype, ovigerous female, 3.8 mm, AM P27186, in front of research station, Lizard Island , Queensland, Australia (14°41'S 145°27'E), medium-fine sand on vey low-intertidal sand flat, P.N. Slattery & J. Oliver, September 1977 (PS 1).

Additional material examined. 22 specimens, 1.3–5 mm, AM P27187 (PS 1) ; 8 specimens, 1.2–4 mm, AM P76888 (PS 1) ; 1 specimen AM P76889 (PS 1) 15 specimens, 1.8–6 mm, AM P25539 (PS 22.5-1) .

Type locality. In front of the research station, Lizard Island, Queensland, Australia (14º41’S 145º27’E) .

Etymology. Named for Margaret Drummond for her enormous contribution to urohaustoriid taxonomy.

Description. Based on holotype, ovigerous female, 3.8 mm, AM P27186.

Head. Antenna 1 peduncular article 1 setal row with only slender setae, setal row proximal pair of setae plumose; accessory flagellum 6 -articulate; primary flagellum 7 -articulate. Antenna 2 peduncular article 4 main setal row with only slender setae, proximal part of row evenly angled; peduncle article 5 not bulbous in male. Mandible incisors almost simple or with 2 weak teeth. Maxilla 1 palp with some setae displaced subapically. Maxilliped palp article 2 inflated distally; article 4 blunt, slightly inflated distally.

Pereon. Gnathopod 1 simple; coxa small, subrectangular or trapezoidal, subequal in size to coxa 2. Gnathopod 2 minutely chelate, propodus palm obtuse. Pereopod 3 coxa large, larger than coxa 4. Pereopod 4 coxa with weak, acute posteroventral lobe. Pereopod 5 basis without mediofacial brush of setae; dactylus with robust setae, arranged in a single row. Pereopod 6 basis fully expanded; merus with slender setae on posterior margin not continuous to apex, a small gap occurs between distal most setae and robust seta at corner; dactylus vestigial, shrouded by robust setae. Pereopod 7 coxa without long posterior spine; basis fully expanded, basis with only slender setae along posteroproximal margin; dactylus vestigial, shrouded by robust setae.

Pleon. Epimeron 2 posteroventral corner broadly rounded, more setose than epimeron 3. Epimeron 3 posteroventral corner with anteriorly curved hook. Uropod 1 inner ramus shorter than outer ramus, not fused to peduncle. Uropod 2 inner ramus shorter than outer ramus, not fused to peduncle. Telson subequal in length and breadth or broader than long, entire.

Habitat. Fossorial, in shallow-water marine sand.

Remarks. There appears to be some variation in the arrangement of robust setae on the dactylus of pereopod 5 in this species. While these are usually arranged in a single row, a few specimens display a paired arrangement, nearly always with one seta smaller than the other.

This species is immediately recognisable by the hook on the ventral margin of epimeron 3. No other species of urohaustoriid exhibits this unusual feature, the purpose of which is unknown at this time. Urohaustorius drummondae is otherwise very similar to both Urohaustorius halei Barnard & Drummond, 1982 , and U. metungi Fearn-Wannan, 1968 . It differs from U. halei in the relative lengths of the uropod 1 rami. It differs from U. metungi only in the presence of the posteroventral hook on epimeron 3.

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

Figures

FIGURE 3. Urohaustorius drummondae sp. nov., female (ovigerous), 3.8 mm, AM P27186, from Lizard Island, Great Barrier Reef.

FIGURE 4. Urohaustorius drummondae sp. nov., female (ovigerous), 3.8 mm, AM P27186, from Lizard Island, Great Barrier Reef.

FIGURE 5. Urohaustorius drummondae sp. nov., female (ovigerous), 3.8 mm, AM P27186, from Lizard Island, Great Barrier Reef.