Sphaeroma annandalei Stebbing 1911

Sphaeroma annandalei Stebbing, 1911

(Figs 1–6)

Sphaeroma annandalei Stebbing, 1911: 181, Pl. X.; Barnard, 1936: 174; 1940: 405; Pillai, 1955: 134, Pl. VII, figs 23–35; Joshi & Bal, 1959: 62; Kensley, 1978: 113.

Sphaeroma irakiensis irakiensis Ahmed, 1971: 77 –79, fig. 1.

Sphaeroma irakiensis bidentata Ahmed, 1971: 79 –80, fig. 2.

Type locality: Port Canning, West Bengal, India.

Material examined. Arvand Kenar, Yadmane Shohadaei Valfajr, Iran, muddy river bank, 20 May 2008, 29°59’015” N, 48°29’038” E; 1 male (11.5 mm); 4 female (8, 9, 9.5, 10 mm) coll. R. Naderloo (ZMH –42309); Arvandroud River (Shatt-Al-Arab), Basrah, Iraq, 10 October 1972, 29°91’ N, 48°58’ E, 8 specimens (USNM 213136); Madras, India, 13 October 1955, 29°91’ N, 48°58’ E, coll. A. Daniel, 2 specimens (USNM 102150); Strait Of Malacca, Selangor, Point Swettenham, Malaysia, from mangroves, 22 Jun 1969, 6 specimens (USNM 128553); Habbanyyah Lake, Iraq. 22.November1982, 52 specimens, males up to 9 mm, females up to 7.5 mm (BM,1982. 552. 30); Bengal, India, (BM, cotype, 1829.12.1. 978-87, Stebbing Coll.)

Description of male (from Iran, Arvand Kenar). Body 1.8 times as long as greatest width, weakly ovate, widest at pereonite 6 (Fig. 1 A). Pereonites 1–7 posterior margin with fringe of small setules. Pereonites 2–7 with coxal plate sutures clearly visible; coxal plates 2–7 with short fine setae on ventral margin, coxal plates 2–3 subtruncate and lateral margin narrower than in posterior plates, more rounded laterally in pereonites 4–7; pereonite 4–7 dorsally with transverse ridges. These ridges are weak and continuous in pereonite 4 and prominent and discontinuous in pereonite 5–7 (Fig. 1 B).

Pleon (Fig. 1 A) dorsal surface with 2 separate prominent tubercles on middle side, each followed by a tiny tubercle distally, either side with a pair of weak nodules above the first suture caudally.

Pleotelson (Fig. 1 A, 12B) dorsal surface with two pairs of prominent blunt tubercles followed by a single median prominent tubercle and flanked on either side by a longitudinal row of three pointed tubercles and in some specimens one or more small tubercles. Posterior margin curved upwards with obtuse narrowly rounded apex.

Antennule (Fig. 1 C) peduncle articles 1–2 with some small sensory palmate setae on ventral margins, article 3 slender and about 3 times as long as article 2; flagellum 11-articled, articles 3–10 each bearing aesthetascs.

Antenna (Fig. 1 D) flagellum 17-articled, each article with an apical tuft of simple setae.

Epistome (Fig. 12 A) with concave lateral margins, triangular apex meeting rostral point of the cephalon,

Right mandible (Fig. 2 C–D) incisor with 2 cusps; spine row of 9 curved, serrate spines; palp article 2 as long as 1, article 2 distolateral margin with 17 biserrate setae; article 3 with about 22 biserrate setae, terminal seta being longest.

Maxillule (Fig. 2 A) lateral endite with simple setae on mesial and outer margins, apical margin with 12 robust, serrate or biserrate and 2 simple robust setae, dorsal surface with 1 robust, long and apically serrate seta; mesial endite with short simple setae on inner margin, apical margin with 3 long, circumplumose robust setae (each of them with some small spines, particularly on apical part) and 2 short plumose setae.

Maxilla (Fig. 2 B) lateral and middle endites each with about 28 finely pectinate robust setae; mesial endite sub quadrangular, with about 27 plumose setae.

Maxilliped (Fig. 6 A) endite bearing 2 terminal circumplumose robust setae, distal margin with about 10 plumose setae, set between fine simple setae, mesial margin sinuate with single coupling hook, inner surface with a row of about 25 long circumplumose setae; palp articles 2–3 bearing dense fringes of long simple setae on superior margin, articles 3–5 with long simple setae on inferodistal angle.

Pereopod 1 (Fig. 3 A) basis superior margin fringed with dense long fine setae and 2 small sensory palmate seta; ischium, merus, carpus and propodus inferior margins fringed with short setae, ischium and merus superior margins fringed with numerous long finely plumose setae; carpus subtriangular; propodus inferodistal angle with 1 biserrate and 1 nodular robust setae; inner surface with transverse row of about 20 long simple or finely plumose setae; dactylus secondary unguis simple, straight, with 3 simple setae at base. Pereopod 2 (Fig. 3 B) similar to pereopod 3 (Fig. 3 C), carpus elongated, superodistal angle with 1 and 4 serrate robust setae in pereopod 2 and 3. Pereopod 4 and 5 are similar as figured (Fig. 4 A, B), shorter than pereopods 1–3. Carpus, propodus and dactylus of pereopods 6 and 7 are similar (Fig. 4 C, D) except in some details such as the number of biserrate robust setae on distal margin of carpus (about 12 in P6 and about 19 in P7).

Pleopod 1 (Fig. 5 A) exopod and endopod with approximately 50 and 16 plumose marginal setae; exopod with a single long, distally biserrate seta on proximal lateral corner and some long simple setae on superodistal margin, lower than marginal setae; sympodite mesial margin with 3 coupling hooks. Pleopod 2 (Fig. 5 B) exopod and endopod shape as in pleopod 1, with approximately 50 and 19 plumose marginal setae; appendix masculina extending beyond endopod, rounded apex with setules on most of surface; sympodite with 3 distomesial coupling hooks. Pleopod 3 (Fig. 5 C) exopod and endopod with approximately 45 and 20 plumose marginal setae; sympodite with 3 distomesial coupling hooks, lateral margin with fringe of thin setae and 3 long simple setae on distolateral corner. Pleopod 4 (Fig. 5 D) rami more oval, endopod narrower than exopod, with a pronounced and curved apical lob; exopod lateral margin with about 18 slender and numerous short setae; sympodite with about 10 long slender setae on distolateral corner and a single serrate seta on mesial margin. Pleopod 5 (Fig. 6 D) exopod with 5 scale patches (3 distally of and 2 under the transverse suture), lateral margin with approximately 40 slender marginal and sub-marginal setae.

Penes (Fig. 6 B) lateral and mesial margins folded, mesial margins covered with several setules.

Uropodal (Fig. 6 C) rami subequal, extending well beyond pleotelsonic apex; endopod margins fringed with numerous simple marginal setae; exopod lateral margin clearly serrate, with 4 –5 prominent and proximally further tiny teeth.

Female. Essentially similar to male.

Remarks. In the original brief description of Sphaeroma annandalei Stebbing (1911), several important characters including pereonite tuberculation, details of mouth parts and pleopods 1–3 were not mentioned or figured. In comparison of the new specimens from the Persian Gulf with cotype material (BM, 1829.12.1. 978-87, Stebbing Coll.), no morphological differences could be found. However, some small variations are seen within the specimens of both populations, these variations are seen in number of uropods teeth (4–5) and number of additional small tubercles on pleotelson. Barnard (1940) reported this species from South Africa with a short description. Based on brief description of Barnard (1940) and our personal examination of the Barnard material (BM, 1937.11. 10. 209, Mouth of Matunzini River, Zululand), there are some differences between Barnard material and S. annandalei these differences are pleonite and pleotelson tuberculation and broadly rounded pleotelsonic apex. Therefore this identification is here regarded as doubtful. In 1955 this species was reported from India by Pillai with the other subspecies, Sphaeroma annandalei travancorensis. Based on a brief description and illustration by Pillai (1955), the S. annandalei specimens are similar to Stebbing’s description. According to Pillai’s (1955) illustrations and description, Sphaeroma annandalei travancorensis differs from S. annandalei in having fewer tubercles on the pleotelson (9 instead of 11), processing more sub-median tubercles on pleon (4 instead of 2) and having a completely rounded pleotelson apex. This taxon could be most probably ‘with concerning the differences cited above’ regarded as separate species. Ahmad (1971) described two subspecies; S. irakiensis irakiensis and S. i. bidentata, from the Shat Al- Arab River. Examinations of topotypic specimens (USNM 213136, 10 October 1972, Basrah, Iraq) reveal that both these subspecies are convincingly identical with S. annandalei. Record of S. annandalei from Brazilian coast (Loyola e Silva 1960) belong to the here described new species.