Ampelisca cyclops Walker, 1904

Momtazi, Farzaneh, 2020, Ampelisca Krøyer, 1842 (Amphipoda: Ampeliscidae) in the Persian Gulf and the Gulf of Oman, Zootaxa 4852 (3), pp. 333-349 : 334-337

Ampelisca cyclops Walker, 1904

( Figs 1–2 )

Ampelisca cyclops Walker, 1904: 253–254 , pl. 2, fig. 14; Pirlot, 1936: 280; K. H. Barnard, 1937: 149; Pillai, 1957: 31–32, fig. 1, 5–9; Nayar, 1959: 8, pl. 2; Rabindranath, 1975: 242, figs. 1–2.

Ampelisca iyoensis Nagata, 1959: 274–277 , figs 9–11.

Ampelisca cyclops cyclops Imbach 1967: 58 , pl. 5, figs D–Q.

Ampelisca cyclops iyoensis Imbach 1967: 58 , pl. 5, figs A–C.

Ampelisca cyclops Walker , variety Imbach, 1967, 58, pl. 5, figs R–T.

Material examined. Female , 14.6 mm ( INIOC2–100 S), Gulf of Oman, Iran (25°15.07’N 60°31.205’E), depth 22 m ; ovigerous female, 14.6 mm ( INIOC2–101 S), Gulf of Oman, Iran (25°12.417’N 60°41.485’E) ; two males, 7.2–10 mm ( INIOC2–103 S), Gulf of Oman, Iran (25°3.807’N 60°7.935’E), depth 22 m ; female, 5.6 mm ( INIOC1–204 S), Persian Gulf , Iran (27°47.21’N 50°43.54’E), depth 67 m.

Type locality. Sri Lanka ( Northern Indian Ocean ) .

Description. Based on female, 14.6 mm (INIOC2–101S).

Head. Equal to three anterior somites, ventral and dorsal margins parallel. Rostrum present, longer than 1/3 of first peduncle article of antenna 1. Eyes present, two pigmented areas, upper at the end of rostrum with lens and the lower at the base of second antenna without lens. Mandibular palp, second article slender. Maxilla 1, inner lobe with few setae. Antenna 1 shorter than peduncle of second antenna, shorter than 1/3 of body length. Antenna 2 longer than half of body length, fourth article longer than fifth article; flagellum with long setae.

Pereon. Gnathopod 1, coxa without tooth on posteroventral corner; propodus shorter than carpus, palm not well defined, without robust seta. Gnathopod 2, coxa with tooth on posteroventral corner; propodus shorter than half of carpus. Pereopod 3, coxa with dentate posteroventral corner; merus without plumose setae on more than half of length in ventral margin; dactylus longer than carpus and propodus. Pereopod 4, dactylus longer than carpus and propodus. Pereopod 5, basis with well developed quadrate posterior projection; carpus longer than propodus. Pereopod 6, carpus subequal to propodus. Pereopod 7, posteroventral lobe reaching end of ischium; ischium longer than merus; merus shorter than carpus, anterior and posterior lobes absent; carpus shorter than propodus, anterior lobe present and posterior lobe absent; propodus rectangular; dactylus tapered, falcate.

Pleon. Third epimeron posterior margin bisinuous, with tooth on posteroventral angle.

Uropod 1 with unequal rami; outer ramus longer than peduncle, with a few robust setae. Uropod 2, rami unequal; subequal to peduncle, rami with numerous setae on rami and peduncle. Uropod 3, rami equal, apices of rami with long apical setae, outer ramus with many setae, inner ramus serrulate. Urosomites 1–2 fused, urosomite 2 with carina and 1–3 dorsal setae. Urosomite 3 without dorsal carina and setae. Telson with marginal setae; distal part with apical projection.

Remarks. Ampelisca cyclops Walker, 1904 was originally described from Sri Lanka. It has a remarkable long rostrum and long setae on the apices of the rami of the second uropod. This species has also been recorded from the Trivandrum coast (Kerala, India) ( Rabindranath 1975; Pillai 1957), Indonesia ( Pirlot 1936), Madras ( Nayar 1959), Gulf of Oman ( Barnard 1937), and Japan (Imbach 1961). These records of A. cyclops are questionable as they do not have complete descriptions. However, the Iranian samples agree with the original description, they could be characterized from it by the unequal rami of the first uropod and the bearing dentate on second and third coxae.

Differences between the records of A. cyclops are provided in Table 1. Since there are no detailed descriptions of other records, it is not possible to compare them in all details. Some characters, such as the dorsal carina length and the number of pigmented eye areas are varied between these records. Also, some studied characters in the present study such as the shape and details of the coxae were not considered in previous studies of Ampelisca , except by Kaïm-Malka (2000).

The present material from the Gulf of Oman contains the largest specimen described until now, varying from 5.6 to 14 mm length. The specimens are most similar to those described by Pillai (1957) from Trivandrum, India.

Figures

FIGURE 1. Ampelisca cyclops Walker, 1904, female, 14.6 mm (INIOC2–101S), Gulf of Oman, Iran. Scale bars: a = 1 mm, b = 0.5 mm.

FIGURE 2. Ampelisca cyclops Walker, 1904, female 14.6 mm, (INIOC2–101S), Gulf of Oman, Iran.