A new species of the genus Copidognathus ( Acari , Halacaridae ) from Zanzibar , Tanzania

A new halacarid species of the genus Copidognathus collected among coralline sediments from the east c oast of Unguja, Zanzibar, Tanzania is described. Dissimilarit es with related species are discussed.


Material and Methods
Specimens were collected from Matemwe, the east coast of Unguja, Zanzibar, Tanzania among Fungia (Anthozoa, Scleractinia) coral rubble.Samples were washed through a 38 µm sieve and then fixed and stored in 80% ethanol.Halacarids were cleared in lactic acid and mounted in glycerine jelly.Drawings were prepared using a camera lucida.Type specimens will be deposited in the museum of Montenegro, Podgorica, Montenegro.
Specimens for scanning electron microscopy were prefixed overnight at 4°C in 2.5% glutaraldehyde, and followed by post fixation in 2% cold osmium tetraoxide.After dehydration through a graded series of ethanol (50-100% at 10% interval) for 30 minutes each, the material was dried at the critical point dryer, and coated with gold palladium in a high evaporator, and then examined with a scanning electron microscope.

Description
Female.Idiosoma 295-317 (holotype: 317) µm long.AD 104-111 (holotype: 106) µm long.Anterior half of AD joining with dorsal part of AE.AD with frontal process and three areolae.Anterior areola oblong; paired crescent shaped middle areolae with 18-20 rosette pores each.Paired ds 1 anterior to middle areolae on AD.Pair of gland pores lie near anterolateral margin of AD anterior to ds 1 .Area between areolae comperises large sized panels (panels not subdivided).Posterior margin of AD with a ridge containing a row of panels, each panel subdivided comprising four to eight small shallow subpanels.OC 82-84 µm long, 51-56 µm width, length to width ratio about 1.6, each with two corneae, areolae with rosette pores medial to corneae and posterolateral to posterior cornea; gland pore lateral to posterior cornea adjacent to lateral margin of OC; pore canaliculus present adjacent to lateral margin of OC.Setae ds 2 located at anteromedial corner of OC.PD 173 -193 (holotype: 193) µm long.PD with two middle and two lateral costae.Each middle costae about 16 µm wide: with one to two rosette pores (each rosette pore with prominent ostium and canaliculi in and around it) and with panels lateral to it (each panel subdivided comprising subpanels) (Figs.1D, 3E, F).Anterior part of middle costae and lateral costae joined together with panels (each panel with subpanels).Area between two middle costae three to six panels wide, panels not subdivided (devoid of subpanels).Setae ds 3 -ds 5 on PD.Gland pores lateral to middle costae on posterior part of PD.AE with three pairs of ventral setae and a pair of epimeral pores.Paired ventrolateral areolae between insertion of legs I and II, paired marginal areolae posterior to insertion of leg II.PE with three ventral and one dorsal seta.GA 150-153 (holotype: 151) µm long, GO 50-59 (holotype: 52) µm long.Distance between anterior end of GO and that of GA subequal to GO length.Paragenital areolae well developed.Three pairs of PGS present.In holotype anterior PGS 22 µm anterior to anterior end of GO; middle pair of PGS posterior to anterior margin of GO, 32 µm apart from lateral margin of GA; third pair near posterior side of GO.Pair of SGS located at the anterior end of genital sclerites.
Gnathosoma 83 -93 µm long.Palp consisting of four segments.Tip of rostrum just passing distal end of P 3 .P 1 and P 3 devoid of any seta.P 2 with one dorsal seta distally.P 4 with three long proximal seta and one minute distal seta.Proto and deutorostral seta situated at the tip of rostrum; tritorostral setae (long maxillary setae of rostrum) located at 0.35 of rostrum length from its tip.Gnathosomal base with a pair of setae (basirostral setae).Rostral sulcus long extends posteriorly just beyond the tritorostral seta.
Etymology.The species is dedicated in honor of Prof. B. C. Guru, Utkal University, Bhubaneswar, Orissa, India, thesis advisor (in D. Sc.) of first author (TC).Remarks.Copidognathus gurui sp.nov. is characterized by two crescent shaped middle areolae on anterior dorsal plate, ds 2 on anteromedian corner of OC, a swollen telofemur I with a trilobed ventrolateral lamella, tibia I with two denticulate proximoventral processes, tarsi III and IV with 4:3 dorsal setae, telofemora III and IV each with one ventral seta.
Copidognathus mumbaiensis is characterised by the presence of a serrated lamella ventrolaterally on telofemur I instead of trilobed lamella.

Figure 3 .
Figure 3. Copidognathus gurui sp.nov.Female.SEM photos.A = Idiosoma and legs, dorsal view.B = Anterior part of idiosoma, dorsal view.C = Magnified view of GO and part of GA.D = PD and OC.E = Magnified view of anterior part of PD.F = Magnified view of part of middle costa on PD.