Halacaridae (Acari) from Gazi Bay (Kenya): description and biogeography ofthree new and two known species

Three new and two known halacarid species are described from benthic and ep iphytic meiofauna samples nearby five seagrass species from the east coast of Kenya (Gazi Bay). Three species belong to the genus Copidognathus (subfa mily Copidognathinae). The present record of C. magnipalpus(Police, 1909) i s the first one for the Kenyan coast, but also for the Western Indian Ocean . C. kenyae sp.n. is new to science because of its combination of character istics: very stout and long rostrum going upto a quarter of palpal tibiotar sus, dorsal seta 2 on ocular plate, epimeral process absent, posterior port ion of anterior dorsal plate with a few rosette pores, posterodorsal plate with two costae 2-3 pores wide, few rosette pores present on lateral side o f posterodorsal plate giving indication of paracostae, tibia I with two sto ut, thick and short setae and one slender seta ventrally. Telofemur I with a thick ventral spine Like seta. Telofemora III and IV devoid of any ventra l seta, tarsi III/IV with four dorsal setae. The resemblance of this specie s to C. curassaviensis is discussed. C. gazii sp.n. is characterised by an anterior dorsal plate with a small frontal projection, an anterior and a bi g posterior areolae joined together; gland pores at the lateral margin; ocu lar plate with an elongated posterior tail; a crescent-shaped elevated ridg e at the middle. Posterodorsal plate devoid of costae and with porose panel . Telofemora III and IV devoid of ventral seta. Porose area on telofemora I /II and tibiae I/II. Tarsi III/IV with four dorsal setae. Rhombognathus scu tulatus Bartsch 1983 (subfamily Rhombognathinae) is widely distributed in t he Indo-Pacific region but this is the first record from the Kenyan coast. One new species of the subfamily Simognathinae was found in the Kenyan samp les. Simognathus tropicalis sp.n. differs from S. uniscutatus as the poster ior epimeral plate is divided into two halves, which is not the case in the latter species. A pointed apical membrane in the second palpal segment cou ld not be distinguished. An elongated ventro-distal portion of tibia I was observed. In addition to the description of the species found in Gazi Bay, an overview of the species known from the East African coast is reported.