Harpinia laevis, Sars, 1891

King, Rachael A., Myers, Alan A. & McGrath, David, 2004, A review of shallow-water Irish and British Harpinia Boeck (Crustacea: Amphipoda: Phoxocephalidae) species including the first detailed descriptions of the males of Harpinia laevis Sars and Harpinia pectinata Sars, Journal of Natural History 38 (10), pp. 1263-1286 : 1273-1277

Harpinia laevis

(figures 7–9)

Harpinia laevis Sars, 1895: 161 , pl. 56; Stebbing, 1906: 145; Stephensen, 1942: 156; Lincoln, 1979: 378, figures 175g, 179a–e.

Material examined

Norway: Risør ( ZMO F13235) . Ireland: North West Mayo ( NMI 22 1998): Station Z 1FA (54°20∞ 52.5N, 11°03∞ 28.44W), 355 m, fine sand; Station Z 12FC (54°20∞ 19.93N, 11°03∞ 40.68W), 347 m, fine silty sand; Station Z 8FA (54°19∞ 47.86N, 11°03∞ 25.20W), 343 m, fine sand (W); Station Z 2FB (54°20∞ 36.35N, 11°03∞ 27.65W), 351 m, fine sand .

Type locality Coast of Norway .

Description

Female. Size: up to 4 mm. Described and illustrated by Sars (1895) and later by Lincoln (1979) from Norwegian specimens.

Male (sexually dimorphic characters). Size: up to 3 mm. Head without spine on dorsolateral margins. Antenna 1 with tuft of long, fine setae on peduncular article 3 and flagellar article 1, article 1 of flagellum elongate, flagellum with five articles, accessory flagellum with four articles. Antenna 2 with small tuft of fine short setae on peduncular article 4. Coxa 1–3 without spines, flagellum with six articles. Gnathopods 1 and 2 with an elongate, narrow propodus, gnathopod 1 with robust seta defining palm. Pereopod 7 basis with six to seven indistinct spines, each with small associated marginal seta. Urosomites narrow, urosomal segment 2 with dorsal elevation anterior to insertion of telson. Epimeron 3 posterodistal corner with excavated notch and small spine. Uropod 3 rami elongate, outer ramus article 2 longer than half length of article 1, without apical seta, inner ramus almost as long as article 1 of outer ramus, without apical seta.

Distribution North-East Atlantic: Norway to north-west Ireland.

Discussion

This is not a commonly collected species. Females are similar to H. crenulata and H. truncata with the rounded epimeron 3 and lack of spines on coxae 1–3. Harpinia laevis females are distinguished by the relatively smooth, rounded basis of pereopod 7 which lack long marginal setae.

The males can be readily identified from those of H. pectinata and H. antennaria by the broadly rounded epimeron 3 (a small notch/spine is present but can be difficult to see). Harpinia laevis males are separated from those of H. crenulata by the shape of the basis of pereopod 7 and the inner ramus of uropod 3, which is almost as long as article 1 of outer ramus and has a long apical seta. The male of H. truncata is undescribed and while it may be similar to H. laevis , the characteristics of the H. truncata female are insufficient to hypothesize the form of the male for comparison.