Sicifera, Cannizzaro & Daniels & Berg, 2022

Cannizzaro, Andrew G., Daniels, James D. & Berg, David J., 2022, Phylogenetic analyses of a new freshwater amphipod reveal polyphyly within the Holarctic family Crangonyctidae, with revision of the genus Synurella, Zoological Journal of the Linnean Society 195, pp. 1100-1115 : 1103-1105

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.