Haustorius orientalis, Bellan-Santini, 2005

Bellan-Santini, D., 2005, European species of Haustorius (Crustacea: Amphipoda: Haustoriidae), with description of a new Mediterranean species, Journal of Natural History 39 (15), pp. 1101-1110 : 1101-1107

Haustorius orientalis n. sp.

( Figures 1–5 )

Material examined

Holotype: one female of 6 mm; paratypes: 24 specimens (seven of them are females with oostegites), Museo Civico di Storia naturale Verona (MVRCr 429).

Type locality

Michmoret beach ( Israel coast), in the sand in the upper part of infralittoral zone.

Diagnosis

Body broad. Head with rostrum exceeding slightly the antennal lobes. Antenna 1, flagellum seven-articulate, accessory flagellum three-articulate. Antenna 2, eight-articulate. Pereiopod 5 very spinose. Pereiopod 7, merus without spines on the posterior margin. Uropod 1, rami unequal in length. Telson with two lateral setae, two plumose setae on the lobe and 12 terminal setae in two rows.

Description

Female, 6 mm. Body broad, eyes not visible in the animal preserved in alcohol. Last segment of pereon produced distally and overhanging reduced urosome. Rostrum exceeding in length slightly the antennal lobes. Antenna 1 with flagellum seven-articulate, accessory flagellum three-articulate. Antenna 2 little longer than A1, flagellum eightarticulate. Mouthparts normal. Mandible with incisor and a triarticulate palp, article 3 with lateral edge bearing 17 small setae in comb row. Maxilla 1 inner plate with 10 marginal setae. Maxilla 2 with inner plate linguiform, outer plate enlarged, lunate, both lined with long fine setae. Maxilliped with triarticulate palp, article 2 enlarged distally, article 3 geniculate. Coxa 1 long and deep, fringed at the posterior part with long plumose setae. Gnathopod 1 simple, carpus enlarged, propodus ovate, dactylus with a distal spine. Coxa 2 ovate. Gnathopod 2 little different from gnathopod 1 but minutely chelate. Coxa 4 larger than coxa 3. Pereiopods 3 and 4 similar, typical for the genus. Pereiopods 5–7 broad. Pereiopod 5 with rounded basis, fringed with long setae, ischium short, merus enlarged, spinose on the surface, fringed with spines and plumose setae, carpus less enlarged than merus, very spinose, propodus very spinose on the anterior margin and with five distal spines. Pereiopod 6, basis rounded, fringed with long setae, ischium short, merus expanded

Figure 4. Haustorius orientalis : pereiopod 3 (1); pereiopod 4 (2); pereiopod 5 (3); uropod 1 (4); uropod 2 (5); uropod 3 (6). Scale bar: 100 mm.

with numerous spines on the surface and on the margins, long plumose setae on the anterior and distal margins, carpus subquadrate covered and fringed with spines, propodus fringed at the posterior margin with spines, seven distal spines. Pereiopod 7, basis large, anteriorly fringed with plumose setae, ischium short, merus produced posteroventrally, anterior margin spinose on the distal half, distal margin spinose, posterior margin without spines, fringed with long plumose setae, carpus and propodus fringed with many spines, short setae on the surface of the carpus. Epimeron 2 with the distal posterior corner quadrate. Epimeron 3 rounded posteriorly, without process, with long plumose setae on the surface. Uropod 1 rami unequal, peduncle and rami armed with strong spines, peduncle with two rows of four spines. Uropod 2, rami unequal, outer ramus longer than inner, peduncle and rami fringed with long setae. Uropd 3, peduncle shorter than rami, outer ramus longer than inner biarticulate, long setae on the distal margin. Telson cleft to the base, consisting of two widely separated lobes with two lateral and 12 distal long setae, two plumose setae on each lobe.

Etymology

The specific name refers to the region of the type locality, in the oriental basin of the Mediterranean.

Relationship

The different species of Haustorius differ from each other in the shape of the rostrum, uropod 1 and pereiopod 7 (denoted 5 by Bousfield 1965 and Mulot 1967). The three European species differ from the American ones essentially in the merus of P7, which has the proximal margin continuous with the posterior margin. It is sharply set off from posterior margin in American species ( Barnard and Karaman 1991; Foster and Lecroy 1991) ( Figure 5 ).

Among the three European species, the Atlantic H. arenarius has a five-articulate accessory flagellum and the merus of P7 with three to four stiff spines groups at the posterior margin. The two other European species are Mediterranean. Haustorius orientalis differs from H. algeriensis in the rostrum exceeding slightly the antennal lobes (equal in length in H. algeriensis ), the flagellum of A2 eight-articulate (nine-articulate in H. algeriensis ), the third article of the mandibular palp with a comb of 17 small setae (14 in H. algeriensis ), the merus posterior margin of P7 not spinose (three spines in H. algeriensis ), and the peduncle of U1 with two clusters of four spines on the ventral margin (a row of spines in H. algeriensis ).

Figures

Figure 1. Haustorius orientalis, habitus. Scale bar: 1 mm.

Figure 2. Haustorius orientalis: antenna 1 (1); antenna 2 (2); maxilla 2 (3); mandible (4); rostrum (5). Scale bar: 100 mm.

Figure 3. Haustorius orientalis: lower lip (1); upper lip (2); maxilliped (3); gnathopod 1 (4); gnathopod 2 (5); maxilla 1 (6). Scale bar: 100 mm.

Figure 5. Haustorius orientalis: pereiopod 6 (1); pereiopod 7 (2); coxa 2 (3); coxa 3 (4); telson (5). Scale bar: 100 mm.