Harpinia antennaria Meinert

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 : 1265-1269

Harpinia antennaria Meinert

(figures 1–3)

Harpinia antennaria Meinert, 1890: 160 , pl. 1, figures 39–41; Chevreux and Fage, 1925: 108, figure 102; Stephensen, 1942: 154–155; Gurjanova, 1951: 369, figure 219; Karaman, 1973: 48, figures 1–3; Drago and Albertelli, 1978: 211; Lincoln, 1979: 372, figures 175a–d, 176a–g; Karaman, 1993: 642–643, figure 441.

Harpinia neglecta Sars, 1895: 153 , pl. 53, figure 1.

? Harpinia plumosa Boeck, 1876: 219 , pl. 8, figure 1 (non Krøyer, 1842: 152).

? Phoxus plumosus Graeffe, 1883: 86 (non Krøyer, 1842: 152).

Material examined

Sweden: Skagerak, Uppsala Expedition 1933, 460 m (SMNH-44714); Bohuslän, Kosterfjord, Rännan, L. Bornö (SMNH-44715); Bohuslän, L. Bornö, Ärtan (SMNH-44718); Bohuslän, Mittskärssanden, 20–26 m (SMNH-44716); Bohuslän, Orrviksnabben, Snäckeberget (SMNH-44717) . Norway: Risør ( ZMO F13235) . Ireland ( NMI 22 1998): Station VV 2 (Margaretta Station, Inner Galway Bay ) 53°13.20∞N, 09°09.20∞W, 20 m, 12 August 1975, muddy sand substratum; Station GB 386, Decca Red D 14, Green B 34, 170 feet, 14 August 1975, soft mud; Irish Sea, 53°39–41∞N, 05°44–46∞W, 15 May 1995; Station GB 320: Decca Red D 8 Green A 46, 126 feet, 19 June 1975, fine sand; Station 5VV ( Margaretta Station , Inner Galway Bay) 53°13.20∞N, 09°09.20∞W, September 1976, 20 m, muddy sand substratum; Station GB 184, Red C 20 Green A 41, 120 feet, 13 August 1974, fine sand. Cork Harbour, Curlane Bank, August 1977, No. 7712 (W); Cork Harbour, Curlane Bank, November 1977, No. 7777 (W) .

Type locality Coast of Norway .

Description

Female. Size: up to 6 mm. Has been comprehensively described and illustrated by Sars (1895) (as H. neglecta ) from the Northern Atlantic and later by Karaman (1993) from the Mediterranean. The Irish specimen illustrated here agrees with both descriptions.

Male (sexually dimorphic characters). Size: up to 4 mm. Head with no distinct spine on dorsolateral margins. Antenna 1 with tufts of long, fine setae on peduncular articles 1 and 3 and flagellar article 1, flagellum with five articles, article 1 of flagellum elongate, accessory flagellum with four articles. Antenna 2 with tufts of fine long setae on peduncular articles 3–4, flagellum with four articles. Coxa 1–3 without spines. Gnathopods 1 and 2 with an elongate, narrow propodus, gnathopod 1 without robust seta defining palm. All appendages less setose than female. Pereopod 7 basis with about five indistinct spines, each with small associated marginal seta. Urosomites narrow, urosomal segment 2 with small irregular dorsal elevation anterior to insertion of telson. Epimeron 3 posterodistal corner with small spine, without oblique row of setae. Uropod 3 rami elongate, outer ramus article 2 shorter than half length of article 1, without long apical seta, inner ramus almost as long as article 2 of outer ramus, without apical seta.

Distribution

North Atlantic Ocean, North Sea, Bering Sea, Kara Sea, White Sea, Murman Sea, Barents Sea, Mediterranean Sea.

Discussion

Harpinia antennaria and H. serrata are the only two species from the North-East Atlantic to possess a large spine on epimeron 3 and to lack spines on the posterodistal margins of coxae 1–3. Females of H. antennaria can be differentiated from H. serrata by the presence of many small marginal spines, with associated long setae, on the basis of pereopod 7 and by the presence of a row of oblique setae on epimeron 3. Males of H. antennaria are most similar to males of H. pectinata with the possession of a distinct spine on epimeron 3 and a narrow propodus on gnathopods 1 and 2, with gnathopod 1 lacking a robust seta on the posterior margin of the propodus. The lack of a spine on the posterodistal margins of coxae 1–3 separates males of the two species. The males of H. serrata and H. dellavallei are unknown but it is possible that their gnathopods 1 and 2 are similar to H. antennaria . If the presence/ absence of spines on coxae 1–3 is not a sexually dimorphic character in this species then H. dellavallei males will have spines on coxae 1–3 which would separate them from H. antennaria males. Harpinia serrata males cannot be clearly defined here from those of H. antennaria , however, it is reasonable to assume that the basis of pereopod 7 would be different in shape and it is possible that the inner ramus of uropod 3 would be shorter than the outer ramus (given that Sars illustrates the female with a short inner ramus). A shortened inner ramus also occurs in males of H. crenulata described here, correlating with a short inner ramus in females of that species.

Lincoln (1979) used the number of marginal setae on coxa 2 (in part) to distinguish between H. antennaria and H. pectinata (females). He recorded that H. antennaria has six to ten setae and H. pectinata three to five. Examination during this study has shown that juveniles of H. antennaria can have four to five setae and so this character alone cannot be used to separate the two species. The presence/ absence of a spine on each of coxae 1–3 posterodistal margins as well as the shape of pereopod 7 basis will easily separate these two species.

Sars (1895) illustrated the male with a distinct spine on the dorsoventral margin of the head. None of the males examined here (including specimens from Sweden) have this spine. We have found that this character is sexually dimorphic in H. pectinata and so may well be in this species. Alternatively, this character may prove to be variable.