Sicifera Cannizzaro & Daniels & Berg 2022, GEN. NOV.

SICIFERA GEN. NOV.

Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: 9E1F37D8-3DF2-458A-B7E7-3A3B43B43738

Type species: Sicifera cahawba sp. nov.

Included species (four): Sicifera bifurca (Hay, 1882) comb. nov., Sicifera cahawba sp. nov., Sicifera chamberlaini (Ellis, 1941) comb. nov. and Sicifera dentata (Hubricht, 1943) comb. nov.

Diagnosis

Medium-sized epigean species, with full eyes and integumentary pigment; interantennal lobe narrow, with rounded upper and lower margins; antenna 1 longer than antenna 2, aesthetascs present on flagellar segments, accessory flagellum two-segmented; antenna 2 of males bearing calceoli on peduncle and flagellum; mandibular molar, incisor and lacinia mobilis well developed, palp three-segmented; maxilla 1 outer plate with seven apical comb-spines; maxilla 2 inner plate with more than five plumose facial setae; propodus of second gnathopod larger than or subequal to first, rastellate setae present or absent on posterior margins of carpus and propodus, propodi anterodistal corners bearing spine-like projections that reduce in size until maturity, palmar margins straight or weakly oblique, armed with multiple robust, bifid setae; coxal plates 1–4 deeper than corresponding somites, longer than broad; pereopod 6 longer than pereopod 7 and much longer than pereopod 5; pereopod dactyli bearing two to five inner marginal setae; subovate coxal gills present on somites 2–6, lanceolate sternal gills present on somites 6 and 7, single pereopod 7 gill present on somite 7; epimera with distinct posterodistal corners, posterior margins with few setae; uronites free or coalesced; uropods 1 and 2 weakly sexually dimorphic; uropod 3 uniramous, ramus one-segmented, shorter than peduncle, with apical robust setae, peduncle often with robust setae; telson of males> 50% cleft-to-base, apices with numerous robust setae, lateral margins bearing plumose setae.

Remarks

Closely allied morphologically with the ‘synurellid’ genera (Synurella, Eosynurella, Diasynurella, Volgonyx and Pontonyx), but can be distinguished from these by using the combination of the following characteristics: the presence of spine-like projections on the anterodistal corner of the gnathopod propodi; presence of two to five inner marginal setae on pereopod dactyli; and male telson> 50% cleft-to-base. Differs from the molecularly allied Amurocrangonyx and the sympatric Crangonyx in the presence of a reduced, uniramous uropod 3; presence of spinelike projections on the anterodistal corners of the gnathopod propodi; and the presence of multiple inner marginal setae on the pereopod dactyli. Differs from other Nearctic genera (Stygobromus, Stygonyx Bousfield & Holsinger, 1989 and Bactrurus Hay, 1902) in possessing pigmented eyes, a uniramous uropod 3 and the presence of spine-like projections on the anterodistal corner of the gnathopod propodi.

Etymology

The genus name Sicifera is formed from the Latin sica (dagger) and ferre (to bear/carry), in reference to the

A NEW CRANGONYCTID AMPHIPOD 1105

characteristic spine-like projections originating from the anterodistal corner of the gnathopod propodi.