Elasmopus alkhiranensis, Myers, Alan & Momtazi, Farzaneh, 2015

Myers, Alan & Momtazi, Farzaneh, 2015, Elasmopus alkhiranensis sp. nov., a new species of amphipod (Senticaudata, Maeridae) from the Persian Gulf, Zootaxa 3973 (1), pp. 185-194 : 186-192

Elasmopus alkhiranensis sp. nov.

( Figs 2–6 )

Elasmopus pectenicrus . ― Nayar, 1959: 27, pl. 9, figs 20–35. ―Nayar, 1967: 152, fig. 10. ― J.L. Barnard, 1970: 125, figs 73– 74. ― Karaman, 1982: 286, fig. 192. ― Ledoyer, 1983: 475, fig. 179–180. ―? Jones, 1986: 150, pl. 41. ― Appadoo & Steele, 1998: 639. ―? Salman, 1998: 250 –255. ― Appadoo & Myers, 2003: 65 , fig. 4. ― Ren, 2012: 204, fig. 88.

Type material. Holotype male ( NHMUK 2015. 2805), mixed rubble NS04, taken by ocklemann dredge on mixed rock/sand benthos at station NS04 phase A1 Sea City, by M. Nithyanandan. 21.10.14. Allotype female ( NHMUK 2015. 2806), same data as holotype.

Other material. 6 males ( NHMUK 2015. 2807–2812), North Gate, Sea City, collected from seaweed and hydroids growing on concrete sides of north tidal gate phase A3 by diving, D. K. Raja 19.4.14; 11 males, 6 females ( NHMUK 2015. 2813–2822), Nuwaiseeb sand beach 3 km south of Sea City at mid-tide from sand core, M. Nithyanandan; 2 males ( NHMUK 2015. 2823–2824), from subtidal seagrass in phase A1 Sea City taken by Ocklemann dredge and small grab, M. Nithyanandan. 14.10.14; 69 males, 114 female and 19 juvenile ( INIOC 1– 24S) from Abu Musa Island (25°52'7.52"N 55°1'6.38"E) at mid-tide from rocky bed covered with algae, 2.5.2014; 3 males and 10 female ( INIOC 1–25S) from Chapahn village near Bushehr (28°20'53"N 51°11'00"E) at mid-tide from sand and coral rubble 3.5.2011; 1 male and 1 female ( INIOC 1–26S) from Chiruyeh village (26°42'42"N 53°43'57"E) from seaweeds 2.5.2011; 6 males and 7 females ( INIOC 1–27S) from Qeshm Island (26°58'5"N 5614'53"E) at mid-tide from sand and coral rubble 20.5.2014.

Row 1: coxa 1, 10.0 mm male, North Gate, Kuwait; 10.0 mm male, Nuwaiseeb, Kuwait; 9.1 mm male, Abu Musa, Iran. Row 2: epimeron 3, 10.0 mm male, North Gate, Kuwait; 10.0 mm male, Nuwaiseeb, Kuwait; 6.7 mm male, Abu Musa, Iran. Row 3: mandible palp, 8.5 mm male, Abu Musa, Iran; 10. 0 mm male, North

Gate, Kuwait; 9.1 mm male, Abu Musa, Iran.

Etymology. Named after the area of the type locality Al-Khiran.

Description. Based on male holotype, 10.0 mm and male (North Gate) 10. 0 mm (mouthparts).

Head. Head with well developed notch; eye lobes truncate; eye ovate. Antenna 1 about half body length, peduncular articles 1 and 2 subequal in length; article 3 about half length of article 2; primary flagellum shorter than peduncle, with 14 articles; accessory flagellum with 2–3 articles. Antenna 2 shorter than antenna 1, articles 4 and 5 subequal in length; flagellum subequal to peduncular article 5, with 6–9 articles. Mandible palp with three articles; article 2 shorter than article 3, article 3 weakly falcate, setiferous along posterior margin. Maxilla 1 inner plate elongate with 3 stout distal setae; outer plate with 7 terminal complexly branched robust setae; palp 2 articulate, terminal article with 1 stout robust and 5 slender distal setae and 1 subdistal seta. Maxilla 2 without oblique setal row. Labium with subacute mandibular processes. Labrum distally rounded.

Pereon. Gnathopod 1 coxa deeper than broad, anterior margin weakly convex; basis stout, weakly excavated for reception of carpus when folded; carpus and propodus subequal, anterior margins heavily setose; palm weakly convex; dactylus fitting palm. Gnathopod 2 coxa narrower than coxa 1, much deeper than broad; basis slender; carpus greatly reduced, cup-shaped; propodus greatly enlarged subovoid; palm a short shelf bordered with robust setae; dactylus very large falciform, greatly overlapping palm. Pereopods 3–4 dactylus short, less than half length of propodus. Pereopod 5 basis evenly convex, weakly crenulate. Pereopod 6 basis, posterodistal margin strongly castelloserrate. Pereopod 7 basis convex, posterodistal margin weakly produced.

Pleon. Epimera 1–3 posterodistal margin weakly serrated; Uropod 1 peduncle with strong distolateral robust seta; Uropod 2 peduncle shorter than rami; inner ramus longer than outer; rami with robust setae. Uropod 3 outer ramus twice length of peduncle; inner ramus about two thirds length of outer. Telson moderately cleft, each distal margin with two long and two short robust setae.

Female (sexually dimorphic characters). Gnathopod 2, carpus well developed, a little over half length of propodus; propodus with palm very oblique, armed with robust setae; dactylus fitting palm.

Variation. Mandible palp article 3 2 × length to 3 × length. Antenna 1 primary flagellum with 14–16 articles. Antenna 2 flagellum subequal with or longer than peduncle. Gnathopod 1 coxa anterior margin weakly convex, straight or weakly concave. Uropod 3 peduncle half length to subequal with outer ramus.

Habitat. Sand and coral rubble, seaweed, hydroids and sea grasses.

Distribution. Mediterranean Sea, Persian Gulf, Madagascar, India, Mauritius, Hawaii. Probably also: Suez Canal, Red Sea, East Africa, South Africa, Sri Lanka.

Remarks. A number of character states were tabulated by Lowry & Hughes (2009) to differentiate between different world materials, including telson clefting and roundness or truncation of head lobe, but these are variable. In material from the Persian Gulf, the male coxa 1 anterior margin can be convex, substraight or weakly concave.

The mandible palp article 3 varies in length. Epimeron 3 is different between E. pectenicrus sensu stricto and other world materials. In E. pectenicrus sensu stricto there is a distinct spine whereas in other materials it is subquadrate and weakly crenulate. However, material from Abu Musa appears to have a spine although it could be described as a relatively deep distal crenulation. Present material from the Persian Gulf resembles Torres Strait material (supposed E. pectenicrus sensu stricto) in having a robust seta on the posterodistal margin of peduncular article 1 of antenna 1, but differs in several other character states. Epimeron 3 does not have a strong spine on the posterodistal margin as in Torres Strait material, but instead, small serrations. Uropod 3 inner ramus is two-thirds length of outer (scarcely half length of outer in Torres Strait material although this character is apparently variable with age (Hughes & Lowry 2011)). In addition, the robust setae on the palm of the male gnathopod 2 are much less stout. On the basis that Torres Strait material is the true E. pectenicrus Bate then present material represents a new species here described as E. alkhiranensis sp. nov. It resembles material from Madagascar ( Ledoyer 1983), India ( Nayar 1959 & 1967), Hawaii ( Barnard 1970), Mauritius ( Appadoo & Myers 2003) and the Mediterranean ( Karaman 1982), although this latter material has antenna 1 without a robust seta on peduncular article 1.

Elasmopus alkhiranensis sp. nov. is primarily an Indian Ocean species (possible records include Red Sea, Persian Gulf, Madagascar, East Africa, South Africa, India, Sri Lanka, Mauritius). Outside the Indian Ocean it occurs in the Mediterranean, where it could be a Lessepsian migrant ( Sezgin et al. 2007), in the South China Sea ( Ren 2012) and in Hawaii ( J.L. Barnard 1970) Indian Ocean material described by the following authors is probably E. alkhiranensis sp. nov. but the descriptions are too incomplete to determine ( K.H. Barnard 1916, 1937 & 1940; Gravely 1927; Schellenberg 1928; Ruffo 1938, 1959 & 1969; J.L. Barnard 1955; Sivaprakasam 1968; Griffiths 1974 & 1975) as well as Elasmopus serrula Walker (1904, 1909 ). Materials from the West Atlantic (Puerto Rico—Shoemaker 1935; Florida—LeCroy 2,000; Brazil—Senna, 2011), East Atlantic ( Reid 1951), Indonesia ( Pirlot 1936) and the Bismarck Archipelago ( Schellenberg 1938), are also too poorly described to allocate to species.

Figures

FIGURE 2. Elasmopus alkhiranensis sp. nov., 6.7 mm (INIOC 1 – 28 S) Abu Musa, Iran.

FIGURE 3. Elasmopus alkhiranensis sp. nov., 6.7 mm (INIOC 1 – 28 S) Abu Musa, Iran.

FIGURE 4. Elasmopus alkhiranensis sp. nov., male holotype, 10.0 mm (NHMUK 2015. 2805) and male (North Gate) mouthparts, Sea City, Kuwait.

FIGURE 5. Elasmopus alkhiranensis sp. nov., Male holotype, 10.0 mm (NHMUK 2015. 2805), Female allotype 9.0 mm (NHMUK 2015. 2806), Sea City, Kuwait.

FIGURE 6. Elasmopus alkhiranensis sp. nov., left to right.