Maera hamigera Haswell, 1880

Appadoo, Chandani, Myers, Alan A. & Fagoonee, Indur, 2002, The genera Quadrimaera and Maera (Amphipoda: Gammaridea: Melitidae) from Mauritius, Journal of Natural History 36 (6), pp. 641-673 : 664-668

Maera hamigera Haswell, 1880

(®gures 14±16)

Maera hamigera Haswell, 1880: 333 , ®gure 21(1); Walker, 1909: 335; Stebbing, 1910: 601; K. H. Barnard, 1916: 196, ®gure 127 (11, 12); J. L. Barnard, 1965: 507, ®gure 16 (in part); Karaman and RuOEo, 1971: 152, ®gures 21±23; Ledoyer, 1982: 523, ®gures 196, 197.

Maera mannarensis Sivaprakasam, 1968b: 274 , ®gures 1, 2; Appadoo and Steele, 1998: 639.

Material examined

1, 1, from Padina sp. and Pocockiella variegata , Flic-en-Flac (20ss16.5¾S 57ss21.7¾E), 3 March 1998. 1, from Turbinaria ornata ; 2, from Pocockiella variegata and Valonia sp. ; 1, from Gracilaria salicornia and Pocockiella variegata, Balaclava (20ss3.7¾S 57ss30.7¾E), 10 September 1998. 2, 1, from coral rubble, Pocockiella variegata and Padina sp. , Flic-en-Flac, 5 April 1999. 1, two juv., from coral rubble and Pocockiella variegata , Flic-en-Flac, 2 August 1999.

Description

Male. Length, 7.2 mm. Body with very short setae on dorsal surface. Head with subocular notch, eyes large and reniform to oval in shape. Antenna 1 peduncle article 1 with one strong robust seta on the ventral margin; article 2, 1.1 times length of article 1; article 3, 0.3 times article 2; ¯agellum 20-articulate: accessory ¯agellum four-articulate. Antenna 2 setose, peduncular articles 4 and 5 subequal; ¯agellum with 14 articles. Mandible palp, article 2, 1.3 times article 3; article 3 with four terminal setae and two lateral setae. Maxilla 1, inner plate with three terminal setae. Maxilla 2, inner and outer plates of subequal in width. Gnathopod 1 coxa produced antero-ventrally, notched on postero-ventral corner and bearing a short seta in the notch, ventral margin with short setae; basis 2.5 times as long as broad; propodus 2.2 times as long as broad and strongly setose; palmar margin convex; dactylus ®tting palm. Gnathopod 2 asymmetrical. Larger gnathopod 2 coxa subquadrate with short setae on ventral margin; basis 2.1 times as long as broad; merus posteroventral margin produced into an acute tooth; carpus subtriangular; propodus 2.2 times as long as broad; palm oblique, palmar margin de®ned by two processes, one small shallow anterior depression bearing a robust seta, one deep medial depression bearing one small and one stout robust seta and a shallow semi-elliptical depression terminating with the de®ning tooth and bearing a strong group of setae. Smaller gnathopod 2, coxa subquadrate with one seta on ventral margin; basis, ischium and merus similar to that of larger gnathopod; carpus longer than that of larger gnathopod; propodus elongate, 2.7 times as long as broad; palm oblique, palmar margin without any noticeable depression bearing ®ve stout robust setae and strong groups of setae. Pereopod 3±4 coxa as long as broad, ventral margin bearing setae; basis 2.8 times as long as broad; merus, carpus and propodus bearing stout robust setae: dactylus not bi®d. Pereopod 5 basis subrectangulate, 1.8 times as long as broad with strong robust setae on the anterior and posterior margins; merus slightly expanded antero-distally. Pereopod 6 basis rectangulate, 1.6 times as long as broad, posterior margin weakly toothed. Pereopod 7 basis posterior margin strongly toothed, 1.5 times as long as broad; merus, carpus and propodus bearing strong setae. Epimeron 3 posterior margin serrated with seven well-developed teeth. Uropod 1 with many robust setae; outer ramus slightly shorter than inner; peduncle 1.2 times length of outer ramus. Uropod 2 inner ramus 1.2 times outer ramus; rami with stout robust setae. Uropod 3 rami ¯attened, three times length of peduncle, bearing stout robust setae. Telson cleft to about 80% its length, lobes bi®d with two strong robust setae in each notch; inner margin of lobe weakly notched, each notch bearing a robust seta.

Female. Length, 6.2 mm. Gnathopod 1 coxa similar to that of male; propodus elongate, 2.8 times as long as broad; palm not de®ned; anterior and posterior margins of propodus with strong setae. Gnathopod 2 coxa, 1.5 times as long as broad; basis 2.3 times as long as broad; carpus subtriangular, 1.6 times as long as broad; propodus 2.1 times as long as broad; palm with poorly de®ned shallow depressions bearing stout robust setae.

Remarks

The species has asymmetrical male gnathopods with oblique palms, the larger gnathopod can either be on the left side or on the right. This species has a head with notch, serrated epimeron 3 and coxa 1 like that of M. octodens . It can be distinguished from the latter by the excavations and arrangement of robust setae on gnathopod 2 palm ( Ledoyer, 1982) and also by the large oblong (reniform) eye.

Type locality. Port Jackson , Australia .

Distribution. South Africa, Red Sea, Mediterranean, India, Madagascar, Mauritius, Australia, Micronesia.