Tayabasa, Kilgallen & Lowry, 2015

Kilgallen, Niamh M. & Lowry, James K., 2015, A review of the scopelocheirid amphipods (Crustacea, Amphipoda, Lysianassoidea), with the description of new taxa from Australian waters, Zoosystematics and Evolution 91 (1), pp. 1-43 : 21

Tayabasa gen. n.

Eucallisoma . - Lowry and Stoddart 1993: 67 (in part, part Eucallisoma ).

Type species.

Eucallisoma barnardi Lowry & Stoddart, 1993, by original designation.

Included species.

Tayabasa includes one species: Tayabasa barnardi (Lowry & Stoddart, 1993).

Diagnostic description.

Mandible lacinia mobilis a cuspidate peg. Maxilla 1 inner plate with pappose setae lining inner margin; palp 2-articulate. Maxilla 2 inner plate broader than outer, inner and outer plates subequal in length. Maxilliped palp article 4 vestigial. Gnathopod 1 coxa large, almost as long as coxa 2, margins slightly tapering distally; basis swollen, with glandular material; dactylus reduced, simple. Pereopod 3 carpus short to long, longer than wide. Pereopod 4 with well-developed, subacute posteroventral lobe.

Etymology.

The name Tayabasa refers to Tayabas Bay, located on the eastern side of Verde Island Passage in the Philippines, close to the type locality of the type species. Gender feminine.

Discussion.

Tayabasa belongs to a closely related and highly derived complex of genera also comprised of Anisocallisoma , Austrocallisoma and Eucallisoma . See discussion under Austrocallisoma for further remarks.

Tayabasa can be separated from Anisocallisoma by the 2-articulate maxilla 1 palp and inner plate with setae lining the inner margin (palp 1-articulate and inner plate with apical setae only in Anisocallisoma ). It differs from Austrocallisoma in peg-like lacinia mobilis, the 2-articulate maxilla 1 palp, and the well-developed gnathopod 1 coxa (lacinia mobilis a stemmed, distally expanded blade, maxilla 1 palp 1-articulate, and gnathopod 1 coxa reduced in Austrocallisoma ). Finally, it can be distinguished from Eucallisoma in the peg-like lacinia mobilis, the vestigial maxilliped palp article 4, and the subacute posteroventral lobe of the pereopod 4 coxa (lacinia mobilis a stemmed, distally expanded blade, maxilliped palp article 4 well developed, and pereopod 4 coxa with a subquadrate posteroventral lobe in Eucallisoma ).