Ampelisca linearis, Momtazi, 2020

Momtazi, Farzaneh, 2020, Ampelisca Krøyer, 1842 (Amphipoda: Ampeliscidae) in the Persian Gulf and the Gulf of Oman, Zootaxa 4852 (3), pp. 333-349 : 344

Ampelisca linearis sp. nov.

( Figs 7–9 )

urn:lsid:zoobank.org:act:18363EBB-CDAE-4DD5-B5F3-D4D5A9551C6C

Material examined. Holotype: female, 6.9 mm ( INIOC1–215 S), Persian Gulf , Iran (27°59.97’N 50°53.98’E), depth 62 m.

Paratypes: eight females, 5.2–6.3 mm ( INIOC1–216 ), Persian Gulf , Iran (27°59.97’N 50°53.98’E), depth 62 m ; two females, 5.9–6.5 mm ( INIOC1–217 ), Persian Gulf , Iran (27°15.56’N 51°3.36’E), depth 70 m ; five females, 4.3–5.3 mm ( INIOC1–218 ), Persian Gulf , Iran (28°54.22’N 49°52.75’E), depth 53 m ; three females, 5.5–6 mm ( INIOC1–219 ), Persian Gulf , Iran (28°14.52’N 50°32.97’E), depth 61 m ; female, 6.5 mm ( INIOC1–220 ), Persian Gulf , Iran (27°29.48’N 51°12.64’E), depth 75 m.

Description. Based on female 6.9 mm, holotype (INIOC1–215S).

Head. Shorter than three anterior somites, ventral and dorsal margins parallel. Rostrum present, longer than 1/3 of the first peduncle article of antenna 1. Eyes present, one pair. Mandibular palp, second article slender. Maxilla 1, inner lobe with 2 setae. Antenna 1, shorter than peduncle of second antennae, shorter than 1/3 of body length. Antenna 2, fourth peduncular article subequal to fifth article, longer than half of body length; flagellum with long setae.

Pereon. Gnathopod 1, coxa without posteroventral dentate; propodus shorter than carpus; palm not well defined and without robust seta. Gnathopod 2, coxa not dentate; propodus shorter than 1/2 carpus. Pereopod 3, coxa without posteroventral dentate; merus with pulmose setae along less than half of anterior margin; dactylus longer than carpus and propodus. Pereopod 4, dactylus longer than carpus and propodus. Pereopod 5, basis with well developed rounded posterior projection; carpus equal or shorter than propodus. Pereopod 6, carpus equal or shorter than propodus. Pereopod 7, posteroventral lobe of basis reaching distal margin of ischium; ischium longer than merus; merus equal or shorter than carpus, anterior lobe present and posterior lobe absent; carpus subequal than propodus, carpus anterior and posterior lobes absent; propodus linear; dactylus straight and tapering.

Pleon. Third epimeron, posteroventral lobe subquadrate. Uropod 1, rami unequal; outer ramus curved, longer than peduncle and naked. Uropod 2, peduncle with only one seta; rami unequal, shorter than peduncle, straight, both rami with only one seta, apices without large apical setae. Uropod 3, rami equal, both rami with many setae, inner ramus serrulate. Urosomites 1–2 with a group of dorsal brush setae and keel. Urosomite 3, dorsal keel present with dorsal brush setae. Telson as long as wide, with apical setae; distal part without apical projection.

Type locality. Persian Gulf, Iran.

Etymology. The term linearis refers to the linear propodus of pereopod 7.

Remarks. Regarding the urosomite decorations and pereopod characters, Ampelisca linearis sp. nov. is most similar to A. misakiensis Dahl, 1944 from Japan and A. insignis (K. H. Barnard, 1916) from South Africa (for differences see Table 2).

The main diagnostic characters of A. linearis sp. nov. are: coxa 1 with no process anteroventrally; dactylus longer than two last articles on pereopods 3–4; few setae on outer ramus of second uropod; and telson as long as wide.

The shape of the first coxa and basis of the seventh pereopod was redrawn in three species ( Fig. 9 ). Other diagnostic characters were tabulated in Table 2.

Ampelisca linearis sp. nov. is distinguished from other species of Ampelisca in the Iranian south coast by its linear propodus of pereopod 7.

Figures

FIGURE 7. Ampelisca linearis sp. nov., female, 6.9 mm, holotype (INIOC1–215S), Persian Gulf, Iran. Scale bars: a = 0.5 mm, b = 0.1 mm.

FIGURE 8. Ampelisca linearis sp. nov., female, 6.9 mm, holotype (INIOC1–215S), Persian Gulf, Iran.

FIGURE 9. The character states of first coxa, head, basis of pereopod 7 and third epimeron of A. misakienesis based on drawings of Imbach (1967) (A), A. insignis based on drawings of Karaman & Barnard (1981) (B) and A. linearis sp. nov. present study(C).