Quadrimaera serrata ( Schellenberg, 1938 )

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 : 652-657

Quadrimaera serrata ( Schellenberg, 1938)

(®gures 6±8)

Maera inaequipes serrata Schellenberg, 1938: 41 , ®gure 18; Barnard, 1965: 510; Ledoyer, 1967: 127, ®gure 9; Sivaprakasam, 1966: 100.

Maera serrata: Sivaprakasam, 1968a: 35 ; RuOEo, 1969: 25; Barnard, 1970: 155, ®gures 96, 97; Ledoyer, 1972: 229, pl. 46; Gri ths, 1973: 286; Ledoyer, 1978: 279; Ledoyer, 1982: 544, ®gure 207; Berents, 1983: 131, ®gure 24; Myers, 1985: 117, ®gure 92.

Quadrimaera serrata Krapp-Sctuckel & RuOEo, 2000, 195.

Material examined

Seven juv., from Gelidiella acerosa (Forskal) Feldmann and Hamel , Flic-en-Flac (20ss16.5¾S 57ss21.7¾E), 12 May 1998. 6, 11 juv., from Gracilaria salicornia (J. Agardh) Dawson , one juv. from Gelidiella sp. , Flic-en-Flac, opposite Klondike Hotel (20ss15.7¾S 57ss22¾E), 12 May 1998. 2, 2, three juv., from Turbinaria ornata , 2, 4, 15 juv., from mixture of coral rubble, Padina sp. , Pocockiella variegata and sponges, 1 and one juv. from Gracilaria salicornia, Balaclava (20ss3.7¾S 57ss30.7¾E), 14 May 1998. One juv., from Turbinaria ornata , 1, 2 and two juv. from spongy red algae and sponges, Bain Boeuf (19ss59¾S 57ss36¾E), 15 May 1998. 1, from coral rubble and Pocockiella variegata , Flic-en-Flac, 15 June 1998. 1, ®ve juv., from Gracilaria salicornia, Souillac (20ss31¾S 57ss30.7¾E), 17 June, 1998. 2, 3, one juv., from Turbinaria ornata and Pocockiella variegata, Bain Boeuf , 28 August, 1998. 5, 4, 33 juv., from Jania sp. and Valonia sp. , Bain Boeuf, 28 August 1998. Two juv., from Sargassum binderi Sonder , 1, from Dictyota divaricata Lamouroux, La Cuvette (20ss00¾S 57ss34.2¾E), 28 August 1998. 1, 1, two juv., from Turbinaria ornata , 4, ®ve juv., from green ®lamentous algae, two juv., from green alga and Pocockiella variegata , 3, 3, ®ve juv., from Gracilaria salicornia and Pocockiella variegata , 6, 5, 30 juv., from red coralline alga, Gracilaria salicornia and sponges, Balaclava, September, 1998. 1, one juv., from mixture of Halodule uninervis (Forskal) Ascherson , Dictyota divaricata and green ®lamentous algae, two juv., from Eucheuma sp. and Gelidiella sp. , 2, 18 juv., from green ®lamentous algae, Albion (20ss13¾S 57ss23.7¾E), 22 October, 1998.

1, from Dictyota divaricata, Roches Noires (20ss6.2¾S 57ss44.5¾E), 10 February 1999. 1, 1, eight juv., from Gracilaria salicornia, Souillac , 25 March, 1999. 2, 2, ®ve juv., from coral rubble, Pocockiella variegata and Padina sp. , Flic-en-Flac, 5 April 1999. 5, 3, nine juv., from Halodule uninervis , Laurencia papillosa (C. Agardh) Greville and Cladophora sp. , 8, 2, 17 juv., from green alga and Cladophora sp. , Albion, 20 April 1999. 2, 11 juv., from Padina sp. and Halimeda sp. , Grand Baie (20ss0.5¾S 57ss34¾E), 5 May 1999. 1, four juv., from Pocockiella variegata and Sargassum sp. , 1 from Cymodocea sp. , Sargassum sp. , Pocockiella variegata , Amphiroa sp. , Bain Boeuf, 16 June 1999. 3, 5, ®ve juv., from Sargassum sp. and Pocockiella variegata, Bain Boeuf , 12 October 1999. 4, 3, ®ve juv., from Sargassum sp. , La Cuvette, 12 October 1999. Two juv., from Halodule sp. , Ulva lactuca Linnaeus and Rhizophora sp. roots, Poste La Fayette (20ss8.2¾S 57ss44.5¾E), 15 October 1999. 3, one juv., from coral rubble, Padina and Pocockiella variegata , Flic-en-Flac, 10 December 1999. 1, 1, one juv., from Padina sp. , Sargassum sp. , Pocockiella variegata, Bain Boeuf , 13 December 1999.

4, seven juv., from mixture of Padina sp. Turbinaria ornata , Caulerpa sertulariodes , Digenia simplex (Wulfen) C. Agardh and Pocockiella variegata, Bain Boeuf , 24 January 2000. 1, from coral rubble, Padina sp. , Pocockiella variegata , Turbinaria ornata , Flic-en-Flac, 27 January 2000. 2, one juv., from Halodule uninervis , Hypnea sp. and Cladophora sp. , Flic-en-Flac, 27 January 2000. 9, 3, one juv., from Laurencia papillosa, Poste La Fayette , 7 February 2000.

Description

Male. Length, 5.7 mm. Head without subocular notch; eyes subround. Antenna 1 peduncle article 1 with three robust setae on ventral margin; article 2, 1.2 times length of article 1; article 3 one-quarter length of article 2; ¯agellum 20-articulate; accessory ¯agellum nine-articulate. Antenna 2 setose, peduncular article 5 shorter than 4; ¯agellum six-articulate. Mandible palp article 2 with about seven robust setae along the outer margin; article 3, 0.8 times article 2, with three terminal setae and seven setae on lateral margins. Maxilla 1 inner lobe with three terminal setae. Maxilla 2, outer plate distinctly wider than inner plate. Gnathopod 1 coxa anterodistally acute but not produced and bearing setae on ventral margin; basis 2.6 times as long as broad, with strong groups of setae on posterior margin; carpus anterior margin with subdistal excavation; propodus with palm convex and bearing short, robust setae; dactylus ®tting palm. Gnathopod 2 coxa subquadrangula r with robust setae on the ventral margin; basis 2.4 times as long as broad and slightly produced antero-distally; postero-distal margin of ischium and merus produced; carpus cupshaped and reduced; propodus subquadrangular, 1.4 times as long as broad, palm transverse, palmar margin weakly scalloped with a deep medial excavation and a V-shaped shallow excavation separating the distal tooth from the palm, palmar processes bearing numerous robust setae; dactylus posterior margin, medially expanded. Pereopod 3±4 coxa subquadrangula r and bearing short setae on ventral margin; basis 3.5 times as long as broad, with robust setae on anterior margin and ®ne setae on posterior margin; merus weakly expanded anterodistally; dactylus distally bi®d. Pereopod 5 basis sub-ovate, 1.8 times as long as broad, anterior margin with robust setae, posterior margin weakly serrated. Pereopod 6 basis 1.3 times as long as broad, anterior margin with long robust setae, posterior margin strongly serrated; merus, carpus and propodus with groups of long robust setae. Pereopod 7 similar to pereopod 6 but basis posterior margin weakly concave and strongly serrated. Epimeron 3 posterior margin with six teeth; antero-ventral margin of epimeron 2 and 3 with one row of robust setae. Uropod 1 peduncle longer than rami; peduncle and rami with many strong robust setae; inner ramus 1.3 times length of outer ramus. Uropod 2 similar to uropod 1 but peduncle subequal to outer ramus. Uropod 3 outer ramus slightly longer than inner ramus and 1.5 times length of peduncle; both rami with long robust setae. Telson cleft to about three-quarters its length, apices bi®d and bearing two stout robust setae on the notch and one on the lateral margin.

Female. Length, 5.7 mm. Gnathopods 1 and 2 very similar to those of male, but palmar margin of female gnathopod 2 convex.

Juvenile, 2.8 mm. Gnathopod 2 medial excavation less pronounced.

Remarks

Q. serrata is the most common Quadrimaera spp. encountered among algae (mostly red and brown) in the shallow intertidal of Mauritius. The species is easily recognized from other Quadrimaera spp. by the toothed epimeron 3 and strongly serrated basis of pereopods 5±7.

Type locality. Apamama , Kiribati .

Distribution. N.E. Australia, Caroline Islands, Fiji, Hawaii, India, Kiribati, Madagascar, Marshall Islands, Mauritius, Red Sea, South Africa.