Rev.Acad. Canar. Cienc, XXII (Num. 3), 75-78 (2010) (publicado en octubre de 2011) FIRST RECORD OF THE SPECIES Microjassa cumbrensis (STEBBING & ROBERTSON, 1891) (AMPHIPODA, ISCHYROCERIDAE) FROM THE CANARY ISLANDS (NE ATLANTIC OCEAN) E. Ramos & R. Riera* Centrade InvestigacionesMedioambientales delAtlantico(CIMASL) ArzobispoEliasYanes, 44, 38206LaLaguna,Tenerife, CanaryIslands, Spain * correspondingauthor: rodrigo(§^cimacanarias.com ABSTRACT The amphipod species Microjassa cumbrensis (Stebbing & Robertson, 1891) is first recordedforthe Canarianarchipelago. This species hasbeen commonly collectedintheEast Atlantic Ocean (coasts ofFrance and England) and the Mediterrranean Sea throughout the last decades. Moreover, accompanying fauna data and sedimentary characteristics of the sampling station are presented. Key words: Amphipoda, Gammaridea, Microjassa, La Gomera, Canary Islands. RESUMEN & Se citaporporprimeravezlaespecieMicrojassa cumbrensis (Stebbing Robertson, 1891) para las islas Canarias. Esta especie se ha colectado de formaperiodica en las ultimas decadas en las costas de Francia e Inglaterra, asi como en el mar Mediterraneo. Ademas, se aportan datos de la fauna acompanante y de las caracteristicas del sedimento de la estacion de muestreo. Palabras clave: Amphipoda, Gammaridea, Microjassa, La Gomera, Islas Canarias. INTRODUCTION 1. In the last decades, sandy seabeds have been neglected in ecological and taxonomic studies inthe Macaronesianregion. However, severalrecentpapers havebeenpublishedrelat- edtoecologyandtaxonomyofmacro-andmeiofaunal assemblages, mainlyfoccusedonpoly- chaetes (Madeira, Nunez et al [4]; Selvagens Islands (Nunez et al [5]; Cape Verde Islands, Nunez et al [6] and the Canarian archipelago, Brito et al [2]). Unfortunately, there are still scarce informationaboutothermacrofaunal components (e.g.Amphipoda, Oligochaeta) ofthe infauna from sandy subtidal seabeds in the Macaronesian region. Thus, biodiversity records are still far from other extensively studied areas (e.g. Atlantic coasts ofFrance and Britain). 75 One ofthe taxonomic groups that belongs to macrofaunal assemblages in sediments are amphipods (gammarids andcaprellids). This taxaismainly composedby surface-deposit feeders that inhabit in the first layers of the sediment surface (Brito [1]), however, amphipods have been received little attention in the last years in ecological and taxonomic studies (Rieraetal [8, 9], Ortiz etal [7]). During an ecological study ofthe sediments in San Sebastian de La Gomera, one specimen ofan unpreviously described species ofgammarid from the Canary Islands was collected. Microjassa cumbrensis has been formerly described intheAtlantic Ocean andthe Mediterranean Sea (Conradi & GonzAlez [3]). MATERIALAND METHODS 2. Samples were collected by means ofa "Cak Foster" dredge, with 28-litres capacity. Sampleswere fixedby4% formaldehydeduring48 hours andthen, sievedina0.5 mmmesh size. Specimens were separated under a stereomicroscope and preserved in 70° ethanol. Specimens were identified by means of a stereomicroscope Nikon SMZ-800 and pictures were taken with an attached camera (EOS-500D). The studied specimens were stored in the invertebrate collection ofCIMA(Centro de Investigaciones Medioambientales delAtlantico SL). A an x" + c_Jo1»_r„.„„, Figure 1.-Mapshowingsamplingstation(•). 76 SYSTEMATICS 3. AMPHIPODA Order Latreille, 1816 Suborder Gammaridea Dana, 1852 Family Ischyroceridae Stebbing, 1899 & Microjassa cumbrensis (Stebbing Robertson, 1891) (Figure 2) & Podocerus cumbrensis Stebbing Robertson, 1891 38. : Microjassa cumbrensis Stebbing, 1899: 240. Studied material.- La Gomera, off San Sebastian de La Gomera harbour (coordinates: 17°1 '08"N/28°07'95"W), female, March 2009, 30 m deep. 1 1 Sediment characterization.- Coarse sands (51%). Organic matter (0.58%). Description.- Length 2.8 mm, whitish. Coxal plate 1 small, plates 2-4 very large and equal, beingbroad the last one (plate 4). Head triangular, with broad lateral lobes. Eyes large and round. Antennae with few long setae (10-15); antenna 1 short, with flagellum articulat- ed (3-4) and accesory flagellum very small (1-articulate).Antenna 2 almost equal than 1, fla- gellum articulated (3-4). Gnathopod 1 propod ovoid, palm with 3 slender spines, dactylus slender with inner margin with tooth. Gnathopod 2 similar to 1, except merus with an enlarged posterior lobe. Pereopods long and slender, 5-7 basis broad and slightly oval. Uropods 1-2 with outer ramus slightly shorter than inner. Uropod 3 with elongate peduncle, inner ramus with an apical spine, outer ramus with distal denticles. Figure 2.- Microjassa cumbrensis. Female. Scale: 0.5 mm. 77 : Accompanying fauna.- The sampling station was dominated by the caprellids Phtisica marina (33 ind.) and Pariambus typicus (30 ind.). Other species with noticeable densities were the gammarid Megamphopus cornutus (13 ind.) and the caprellid Pseudoprotellaphasma (13 ind.). Distribution.- Mediterranean Sea. EastAtlantic Ocean (Conradi & Gonzalez [3]). ACKNOWLEDGEMENTS 4. We are grateful to Dr. Manolo Ortiz (Centro de Investigaciones Marinas, University ofLa Habana, Cuba) for his encouragement and interchange ofideas. To Dr. Oscar Perez (Centro de Investigaciones Medioambientales delAtlantico, CIMASL) formap preparation. REFERENCES 5. [1] BRITO, M.C. 1999. Estudio delas comunidades intersticialesdelsebadalfCymodocea nodosa,) en Canarias, con especial referenda a los anelidospoliquetos. 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