Poligarida, Bamber & Marshall, 2013

Bamber, Roger N. & Marshall, David J., 2013, Tanaidaceans from Brunei III. A New Genus and Two New Species of Shallow-water Sphyrapodids (Crustacea: Peracarida: Tanaidacea) from the South China Sea, Species Diversity 18, pp. 255-267 : 256

Family Sphyrapodidae Guţu, 1980 Subfamily Sphyrapodinae Guţu, 1980 Genus Poligarida gen. nov.

Diagnosis. Sphyrapodid tanaidacean with no mandibular palp, no maxillular palp, two segments in accessory flagellum of antennule, and no squama on antenna; mandibular molar bearing distal setae but no grinding or cutting surface; carapace wider than long; pereopods without complex distal setation, and without hook-like apophyses on their bases. All setation sparse and simple.

Type species. Poligarida beni sp. nov. Other species: Poligarida keriakis sp. nov.

Etymology. after Poli, the original (7th century) name of Brunei, when it was a subject state of the Srivijayan Empire, and garida from the Greek, meaning “shrimp” (feminine).

Remarks. The absence of a maxillular palp in these taxa is unique for the family (although palp condition was not recorded in the unrelated pseudosphyrapodin Pseudosphyrapus malyutinae Błażewicz-Paszkowycz, Bamber & Jóźwiak, 2012 ; see Błażewicz-Paszkowycz et al., 2013), and thus distinguishes this genus from all others; nine specimens were dissected to confirm that it had not been simply missed in the preparation of the material. The additional absence of a mandibular palp, and the peculiar mandibular molar with relatively long distal setae but no grinding or crushing surface, suggest a particular feeding strategy; the gut contents of prepared specimens appeared to be of finely particulate detritus, possibly plant material, but no structure was evident.

The absence of a mandibular palp is a diagnostic character of the subfamily Sphyrapodinae . Of the three previously-known genera, Sphyrapoides (only) has a squama on the antenna, while Sphyrapus Norman in Sars, 1882 has a reduced accessory flagellum on the antennule, of one or fewer segments (see Błażewicz-Paszkowycz et al. 2011). [“ Sphyrapus ” stebbingi Richardson, 1911 is tentatively reassigned here to Pseudosphyrapus : although the original description is scant, this species is not a Sphyrapus ; Richardson (1911) did describe a two-segmented accessory flagellum, and she made no mention of a squama on the antenna].

Only Ansphyrapus shares with Poligarida gen. nov. the absence of a mandibular palp and antennal squama, and the presence of a two-segmented accessory flagellum on the antennule. As well as lacking a maxillular palp, Poligarida is distinguished from Ansphyrapus in the conformation of the mandibular molar and the antennal peduncle (see below), in having no hook-like apophyses on the bases of the pereopods, in having only setae on the carpi and propodi of the pereopods (variously setae and spines in Ansphyrapus ), and in lacking the complex distal spinulation of the posterior pereopods found in Ansphyrapus .

Poligarida is the only sphyrapodin genus to have the carapace wider than long, a condition only recorded previously in this family in a few species of Kudinopasternakia Guţu, 1991 (e.g., Santos 2007).

Equally, all the other species of the Sphyrapodinae have a short second article of the antennal peduncle, while the longer second article found in Poligarida , much longer than the third article, is characteristic of all the genera of the other sphyrapid subfamily, the Pseudosphyrapodinae Guţu 1980 . This feature, together with the varied presence of an antennal squama and the plesiomorphic antennule with a twosegmented accessory flagellum throughout the genera of the whole family, brings into question the validity of the separation of these two subfamilies on the grounds of the presence or absence of the mandibular palp alone.