Elasmopus menurte Barnard, 1974

Momtazi, Farzaneh, Sari, Alireza & Maghsoudlou, Abdolvahab, 2014, New species and new record of hadzioids (Amphipoda: Senticaudata, Hadzioidea) from the Persian Gulf, Iran, Zootaxa 3881 (5), pp. 440-452 : 441-442

Elasmopus menurte Barnard, 1974

Elasmopus menurte Barnard, 1974: 21 , figs 14, 15. Lowry & Stoddart, 2003: 178.— Appadoo & Myers, 2003: figs 1, 2.— Hughes & Lowry, 2011: 608 .

Elasmopus ecuadorensis hawaiensis .— Appadoo & Steele, 1998: 639.

Material examined. 1 male, 12.3 mm, INIOC 1-18S, Qeshm Island (26°43'58"N 55°50'2"E), intertidal zone, January 2014. 4 male and 5 females, INIOC 1-19S, Qeshm Island (26°43'58"N 55°50'2"E), intertidal zone, January 2014.

Type locality. Bunker Bay, Western Australia.

Description. Based on male, 12.3 mm. INIOC 1-18S ( Fig. 2 ).

Head. Eyes ( Fig. 2 ) subovate; lateral cephalic lobe broad, apically round, anteroventral margin with notch/slit, anteroventral corner rounded. Antenna 1 ( Fig. 2 , A1) longer than antenna 2; peduncular article 1 subequal to article 2; article 2 length 1.8 × article3; accessory flagellum 3-articulate; flagellum 29-articulate. Antenna 2 ( Fig. 2 , A2) peduncular article 3 with 3 robust setae on antero-distal margin, article 4 subequal to article 5; flagellum 6- articulate.

Upper lip ( Fig. 3 , U.L) with apical setules. Lower lip ( Fig. 3 , L.L) with subacute mandibular lobes. Mandible ( Fig. 3 , RMd, LMd.) incisor a smooth cutting edge with 3 accessory setae; palp well developed, 3-articulate; first article length 2.17 × second article; article 2 length 1.16 × third article; article 3 falcate, with setal row and 3 long apical setae on inner margin, and also several long setae on outer margin. Maxilla 1 ( Fig. 3 , Mx1) inner plate with 2 plumose apical setae and fine setae on lateral margins, outer plate with 7 setal-teeth; palp 2-articulate, with apical long setae and fine setae on apical margin. Maxilla 2 ( Fig. 3 , Mx2) inner plate with several long setae and some fine setae along lateral margins, outer plate with several apical and some fine setae along lateral margin. Maxilliped ( Fig. 3 , Mxp) palp 4-articulate, article 2 longest.

Pereon. Gnathopod 1 ( Fig. 4 , G 1♂) coxa anteroventral corner produced, rounded, anterior margin slightly concave; carpus 1.76 × as long as broad, subequal in length to propodus, with slender setae on anterior and posterior margins; propodus with 2 semicircular comb rows of setae on inner medial face, palm subacute, convex, defined by posterodistal corner and posterodistal stout seta. Gnathopod 2 ( Fig. 4 , G 2♂) coxa subrectangular, ventral margin with 2 long setae and a few short-setae, basis slender; merus with rounded posterodistal corner; carpus elongate, projecting between merus and propodus; propodus covered with slender setae along posterior margin, palm subacute, slightly sinuous, about half length of propodus, with round distomedial shelf armed with 6 stout setae, medial face of hand with ridge hidden by setae, distal end of ridge with hump and 5 stout setae, palm with a quadrate-shaped projection medially and proximal protuberance with 2 stout setae along the palm; dactylus reaching end of palm, closing along margin of palm, apically subacute. Pereopod 3 ( Fig. 4 , P3) coxa subrectangular. Pereopod 4 ( Fig. 4 , P4) coxa posteriorly excavate. Pereopod 5 ( Fig. 4 , P5) basis expanded; posterior margin slightly convex, without long slender setae, posteroventral corner subquadrate. Pereopod 6 ( Fig. 4 , P6) basis posterior margin slightly convex, without long slender setae, posteroventral corner subquadrate. Pereopod 7 ( Fig. 4 , P7) basis posterior margin convex, without long slender setae, posteroventral corner subquadrate; propodus slightly expanded postero-distally.

Pleon. Pleonites 1–3 ( Fig. 2 ) dorsally smooth, without setae, spines or carinae. Epimeron 1 ( Fig. 3 , EP) with lateral ridge, posteroventral corner subquadrate with small tooth and sinus, posterior margin serrate. Epimeron 2 ( Fig. 3 , EP) posteroventral corner acute with small tooth and sinus, posterior margin serrate, ventral margin with three groups of 1 – 3 stout setae. Epimeron 3 ( Fig. 3 , EP) ventral margin with three groups of 1 – 3 stout setae, posterior margin serrate, postero-ventral corner with small acute tooth and sinus. Urosomite 1 ( Fig. 2 ) with small hump and some fine setae. Uropod 1 ( Fig. 2 , U1) peduncle with basofacial robust seta. Uropod 2, ( Fig. 2 , U1) rami length subequal to peduncle. Uropod 3 ( Fig. 2 , U1) rami distally truncated, apical robust setae long and short; inner ramus short, about 1.14 × outer ramus; outer ramus subequal in length to peduncle. Telson ( Fig. 3 , T) short, slightly broader than long, deeply cleft, truncate distally, apical margins concave, each lobe with 3 apical stout setae, without stout setae on lateral margins; inner apical lobes longer than outer lobes.

Female. Gnathopod 1 ( Fig. 4 , G1♀) as same as male. Gnathopod 2 ( Fig. 4 , G2♀) coxa subrectangular, about 2 × as long as broad, ventral margin with few short-setae; carpus broadly projected between merus and propodus; propodus expanded, with slender setae along anterior and posterior margins, palm acute, straight, with some stout and fine setae along palm; dactylus reaching end of palm, closing along margin of palm.

Distribution. Studied materials are found as epifauna on rocky coasts and among algae in mid intertidal zone of the Persian Gulf.

Variation. The third article of accessory flagellum in some specimens was vestigial. In material examined the protuberance and dentate along palm of second male gnathopod was varied from markedly and quadrate dentate to vestigial protuberance. The hump on first urosomite was different from triangle specified to vestigial hump. Also in the outer ramus of third uropod has been shown different number of apical setae.

Remarks. Elasmopus menurte Barnard, 1974 is a new member of the genus Elasmopus in the Persian Gulf. Previously, Jones (1986) and Salman (1998) reported E. pectenicrus from the Persian Gulf. The genus Elasmopus has more than 100 described species. Elasmopus menurte Barnard, 1974 is similar to E. japonicus Stephensen, 1932 , and E. woodjonesi Hughes & Lowry, 2011 in having a dorsal hump on the first urosomite (Vader & Krapp- Schickel 2012). However the specific characters on second male gnathopod differentiate E. menurte from E. woodjonesi . There are more similarities between E. menurte and E. japonicus in the second male gnathopod as Barnard (1974) believed that E. menurte and E. japonicus Stephensen (1932) differ only at subspecific status. Based on Barnard (1974) E. menurte differs from E. japonicus in the much lower crest of urosomite 1 and in telson characters. The type locality of E. menurte is the south coast of Western Australia. Other records belong to the north coast of Western Australia ( Hughes & Lowry 2011) and Mauritius ( Appadoo & Steele 1998; Appadoo & Myers 2003). There was some differences between descriptions of Australian ( Barnard 1974), Mauritian ( Appadoo & Myers, 2003) and Persian Gulf material. Mainly differences were in the first male gnathopod and mandibular palp. However, carpus length in the first male gnathopod was equal to propodus in studied material; it was slightly longer in Australian specimens and shorter than the propodus in Mauritian specimens. The Persian Gulf materials were specified by some stout setae on the third article of the second antennae and the shorter length of the first article of the mandibular palp that is less than half of the second article whereas in the Australian and Mauritian materials it exceeds 0.6 times the second article. Unlike the distinct serration on the posterior margin of the epimera in the Persian Gulf material, it is not mentioned in descriptions of E. menurte by Barnard (1974) and Appadoo & Myers (2003). However, Vader and Krapp-Schickel (2012) assigned it in the matrix of Elasmopus species characters.

Figures

FIGURE 2. Elasmopus menurte Barnard, 1974 male, 12.3 mm, INIOC 1 - 18 S, Qeshm Island, (26 ° 43 ' 58 " N 55 ° 50 ' 2 " E). Scale a = 0.5 mm, b = 1 mm.

FIGURE 3. Elasmopus menurte Barnard, 1974 male, 12.3 mm, INIOC 1 - 18 S, Qeshm Island, (26 ° 43 ' 58 " N 55 ° 50 ' 2 " E). Scale a, b = 0.5 mm.

FIGURE 4. Elasmopus menurte Barnard, 1974, male, 12.3 mm, INIOC 1 - 18 S, Qeshm Island, (26 ° 43 ' 58 " N 55 ° 50 ' 2 " E), G 1 & 2 ♀; female 11.7 mm, INIOC 1 - 19 S Qeshm Island. Scale a = 1 mm.