Neotenorchestia kenwildishi, Wildish, 2014

Wildish, David J., 2014, New genus and two new species of driftwood hoppers (Crustacea, Amphipoda, Talitridae) from northeast Atlantic and Mediterranean coastal regions, Zoosystematics and Evolution 90 (2), pp. 133-146 : 137-138

Taxon classification Animalia Amphipoda Talitridae

Neotenorchestia kenwildishi sp. n.

Neotenorchestia kenwildishi : Wildish et al. 2012: 2677; Pavesi et al. (2014), as unknown taxon.

Type material.

Holotype–immature male of 7.2 mm total body length (NHMUK 2014. 397) and slide preparation from this individual (NHMUK 2014. 397). Nine juvenile paratypes (NHMUK 2014. 398 - 406) and 2 immature females (destructively sampled for temporary slide mounts and mtDNA analysis) removed from a cast-up driftwood log resting at the base of the seawall in the Enteromorpha zone by K.J. Wildish. The driftwood log had been tethered to an old cattle fence on the shore, so it could not float away. It was sampled on 14th June 2011, 23rd July 2011 and 13th August, 2011 from the Swale, near Kingsferry Bridge, U.K.

Type locality.

Approximately 0.5 km west of Kingsferry Bridge, The Swale on the mainland shore in a single rotting driftwood log (~ 3 × 0.5 × 0.5 m) determined to be of Douglas fir by Dr. P. Gasson, Kew ( Pavesi et al. 2014). GPS position: 51° 23.97'N, 00° 43.56'E.

Maximum body length.

Unknown, the largest found was an 8.9 mm TBL immature female. Mature adults predicted by relative growth methods to be 12 to16 mm total body length ( Pavesi et al. 2014).

Diagnosis.

Neotenorchestia kenwildishi sp. n., can readily be distinguished from other driftwood hoppers of the genus Macarorchestia by its medium size eyes (versus small) and unreduced pleopods (rami sub-equal to basis, versus rami shorter than basis).

Description.

Based on immature male holotype of 7.2 mm total body length. Figs 4 and 5.

Head deeper than long (1: 0.5); eyes medium/large, round and greater than half the head length. Antenna 1 flagellum 4-articulate. Antenna 2 flagellum 13-articulate. Peduncle not incrassate.

Mouthparts. Upper lip with minute setae on the apical margin. Lower lip deeply cleft and with minute setae on the inner face. Maxilla 1 inner fig slim and with two terminal, plumose setae; inner margin with long fine setae; outer fig with a vestigial palp, apical robust setae curved inwards, some simple and others serrated on the inner edge. Maxilla 2 with inner fig subequal to the outer, inner with a single, plumose seta and fine marginal setae below it; both inner and outer figs with long, simple robust setae which curve inwards. Left mandible with a 4-dentate lacinia mobilis, 6-dentate incisor, strong molar process and setose accessory blades. Maxilliped with 3 strong apical teeth on the inner fig; inner, outer and palp edged with simple, robust setae; palp large and 3-articulated.

Peraeon. Gnathopod 1 weakly subchelate, palmate lobes on propodus and carpus. Gnathopod 2 weakly subchelate with dactylus shorter than the propodus lobe; palmate lobes on propodus, carpus and merus. Peraeopod 3 lacks a dactylus notch ("pinched unguis"), but this is present in an immature female. Peraopod 5 shorter than peraeopods 6 and 7, the latter not sexually dimorphic in the immature male.

Pleosome. Pleopods large and well developed, with 6-7 ramal segments in the endopod, 8 segments in the exopod; rami subequal to basis with paired coupling spines on the inner, distal margin of the basis; 6 simple setae present on the basis of pleopod 1.

Urosome. Uropod 1 rami subequal to peduncle. Peduncle with 2 rows of 2 robust setae. Terminal setae on each ramus consists of 1 large and 1 or 2 smaller robust setae. 3 interamal robust setae on inner and 2 on outer ramus.

Sexually dimorphic differences.

Based on immature female of 8.9 mm total body length.

In the absence of sexually mature males and females the only unique female characters found were: absence of palmate lobes on propodus and carpus of gnathopod 1, presence of pinched unguis on peraeopod 3, and presence of small, rudimentary oostegites on coxae of peraeopods 2-5.

Etymology.

The name honours Kenneth J. Wildish who discovered and collected the new taxon in the Swale during the summer of 2011.

Epidermal pigment patterns.

Absent.

Distribution.

Known only from the type locality.

Key for northeast Atlantic/Mediterranean Macarorchestia and Neotenorchestia gen. n.