Contributions to Zoology. 71 (4) 147-158 (2002) SPB Academic Publishing bv, The Hague Oligochaetes from underground waters of Oman with descriptions of two new of Phreodrilidae Antarctodrilus arabicus n. and species (Oligochaeta): sp. Phreodrilus stocki n. sp. Stygofauna of Oman, 7* ¹, ³ Martínez-Ansemil Narcisse Giani ² & Beatrice Enrique ¹, Sambugar 1 Bioloxia Bioloxia Departamento de Animal, Vexetal e Ecoloxia, Facultade de Ciencias, Universidade da 2 Coruna, Campus da Zapateira s/n, E-15071 A Coruna, Spain, [email protected]; Centre d’Ecologie des Systemes Aquatiques Continentaux, UMR C5576 CNRS, Universite Paul Sabatier, 118 route de Narhonne, 3 F-31062 Toulouse Cedex, France, [email protected]; Museo Civico di Storia Naturale, Lungadige Porta Vittoria 9, 1-37126 Verona, Italy, [email protected] Keywords: Groundwater oligochaetes, Phreodrilidae, new species, Oman, biogeography Abstract driloidinae), previously known from Puerto Rico and Belize in the Atlantic western Ocean, represents a large extension ofits known distribution area. The study oftwenty-nineoligochaete samples collected in 1996 by J. H. Stock and J. J. Vermeulen (University ofAmsterdam), in the of allowed draw in- Sultanate Oman, us to up an initial of the Arabian ventory of the freshwater oligochaete fauna pe- Contents ninsula, a fauna totally unknown until now. The 147 specimens examined belong to nine species offour families: Phreodrilidae, Introduction 147 Naididae, Tubificidae and Enchytraeidae. The Phreodrilidae(2 Material and methods 148 whilst species) represent more than half ofthe total specimens; Systematic account 148 the rest belong mainly to the Naididae. Faunistic remarks 155 arabicus Two new species ofPhreodrilidae(Antarctodrilus Acknowledgements 157 described. Both n. sp. and Phreodrilus stocki n. sp.) are belong References to 157 the subfamily Phreodrilinae,untilnow not reported from north ofthe tropic ofCapricorn. Otheridentifiedspecies include Dero Allonais and Doliodrilus (Dero) zeylanica, paraguayensis puer- recorded subterranean toricensis, which are for the first time in Introduction habitats. the of the of These studies confirm hypothesis presence Marine oligochaetes of the Arabian Gulf have been Phreodrilidae in the Arabian peninsula as relict taxa inhabiting studied refuges in hyporheic/groundwater habitats. by Erseus( 1985, 1986a, 1986b, 1988, 1989) marine The of an fauna with phyletic presence oligochaete but the freshwater oligochaete fauna of the Ara- affinities in underground waters already highlighted in Europe bian peninsula was totally unknown until now. We now equally applies to the Arabian peninsula with the discov- had the of of the tubificid and in the opportunity studying twenty-nine oligo- ery genera Aktedrilus Doliodrilus chaete from underground habitats ofOman. As these genera already are well samples this part of the world forwarded known from littoral marine or brackish water with a wide the to one of us (BS) by R. Vonk of the University of range of salinity, we have additional evidence that the migra- Amsterdam. The material was collected by J. H. tion of interstitialmarine meiobenthic tubificid species through Stock and J. J. Vermeulen of the of water of be the University decreasing salinity may a way of colonising subterranean freshwaters. Amsterdam in 1996, during an expedition in the The Doliodrilus arid present record of puertoricensis (Limno- Sultanate of Oman, an country situated along Stygofauna Oman 7. issue, nr. is published & in Muss. Nat. of nr. The previous 6, by Ruffo Holsinger Boll. Civ. Stor. Verona - Botanica, Zoologia, vol. 27 (2003) Downloaded from Brill.com10/05/2021 05:43:57PM via free access 148 E. Martinez-Ansemil, N. Giani & B. Sambugar - Oligochaetes from underground waters of Oman - The the south-eastern margin of the Arabian peninsula. Remarks. branchial fossa displays one pair They sampled several different subterranean habi- of parallel palps and three pairs of gills. The meas- tats in which oligochaetes were found. The habi- urements for the anterior ventral setae are 50-70 the tats include the interstitial coarse sediments of dry pm, for posterior ventral setae 44-60 pm, for beds and the needle 34-48 and for the hair stream (wadis), wells, springs, one cave. setae pm setae This paper presents the results of the identifica- 120-180pm. These setal lengths are within the range tion of this material including the description of recorded for African (Grimm, 1987) and Caribbean two new species of Phreodrilidae, a family largely specimens (Dumnicka, 1986a; Chagne & Giani, distributed in the southern and but lie the lower end of The hemisphere reported 1998), they at range. twice from the northern from Sri Lanka 1914 only one: Dero (A.) africana Michaelsen, has much larger intermedi- (Stephenson, 1913) and Morocco (Giani et al., 1995). setae (Grimm, 1985). The presence of ate teeth in the needle setae was noted in the new material, a feature already reported for Dero (Aulo- Material and methods phorus) furcata (Sambugar, 1986; Grimm, 1987). The specimens were collected in wells using a Cvetkov closing Distribution and habitat. - Known vertical in the of and the Cosmopolitan. net, and hyporheon wadis, springs to inhabit lentic and lotic habitats of surface ofthe Bou-Rouch from the wa- cave by means pump. Samples cave with in the As and some springs were collected in superficial waters a ters, mainly intertropical region. regards handnet. subterraneanwaters it was previously foundin wells labora- The formalin preserved samples were sorted in the of West Indian Islands (Dumnicka, 1986a) and in tory under a dissecting microscope andtransferred to 70 % etha- Morocco (Giani, unpublished data). nol. In the field, some physical-chemical parameters were directly the electrical in mS/ measured, e.g., conductivity (eC pS/cm or cm) and the water temperature. The geographical position of the sampling stations is given Dero (Dero) zeylanica Stephenson, 1913 by UTM coordinates. Every site has its code in relation to a station list provided by the University of Amsterdam. Examined material. - Eight immature specimens from a well at All specimens were mounted in Canada balsam, most ofthem Dibab (96/23), UTM 0700988/2553839,eC 400 pS/cm, 25 March as whole mounted worms. Mature specimens were previously 1996,Legit: J. H. Stock. stained with Harris haematoxylin and some were dissected un- der a stereo-microscope. Drawings were made by means ofa - in camera lucida. Remarks. The material collected Oman is mor- of is stored in the The type material the new species collec- phologically in accordance with the literature data tions of the Zoological Museum of Amsterdam (ZMA). Other (Sperber, 1948; Brinkhurst & Jamieson, 1971). reference specimens are in the authors’ own collections. Distribution and habitat. - Previously known only from Southern India and Sri Lanka. Not Systematic account previously found in subterranean waters. Family: NAID1DAE Subfamily: Naidinae Allonais Dero (Aulophorus) furcata (Muller, 1773) paraguayensis (Michaelsen, 1905) Examined material.-Twelveimmaturespecimens: 1 from inter- Examined material. - Thirty-five immaturespecimens, all col- stitial waters of a spring formed in 1995 in Bait Qura lected by J.H. Stock: 10 from a well at Majaz Al Sugra (96/65), Rustaq, (96/69), UTM 0443405/2587376,eC 818 pS/cm, I April 1996, onplantation, UTM 0483567/2679077,eC 1004 pS/cm, 30 March J. H. Stock; 3 from a well in South Dahariz UTM 1996; 2 from interstitial waters of a spring formed in 1995 in Legit: (96/99), Rustaq, Bait Qura (96/69), UTM 0443405/2587376,eC 818 pS/ 0196965/1883319,eC 4210 pS/cm, 5 April 1996, Legit: ,1. H. 1996; from 0254392/ Stock; 1 from a well in the A’Muotazah area (Salalah cm, 1 April 5 a well at Marbat (96/84), UTM Centre) (96/100),UTM 189032/1882511,eC3490 5 1996, 1879929, eC 2.35 pS/cm, 4 April 1996; 1 from a well at Dahariz pS/cm, April South (96/99), UTM 0196965/1883319,eC 4210 pS/cm, 5 April Legit: J. H. Stock; 3 from surface waters of the spring head of Wadi Darbat catchment 1996; 17 from a well at Auwqad South (96/101), UTM 0184857/ the (96/103), UTM 0230717/1897256, 1881731, eC 4010 pS/cm, 5 April 1996. eC 754 pS/cm, 5 April 1996, Legit: J. H, Stock; 2 from surface Downloaded from Brill.com10/05/2021 05:43:57PM via free access Contributions to Zoology, 71 (4) - 2002 149 waters ofthe Ain Hamran spring (Salah UTM region) (96/106), lip associated with circular muscle. Cutaneous glands 0210592/1892363, eC 576 gS/cm, 6 April 1996, Legit: J. H. in more or less arranged parallel rows, particularly Stock; 2 from the interstitial waters ofWadi Nakhal (96/126), setal each numerous at level of segment. Clitellum UTM 0584918/2592170, eC 1210 pS/cm, 9 April 1996, Legit: XII-X1II J. J. Vermeulen. extending over with glandular cells ar- in ranged more or less parallel rows. - Ventral from 11 1 Each bundle Remarks. The material from Oman is morpho- setae (Fig. A). of of consisting a pair dissimilar one logically in accordance with the literature data (e.g. setae; single and thin Sperbcr, 1948; Brinkhurst & Jamieson, 1971). The pointed (1.5-1.8 pm wide), without nodu- needle setae in lus, the other bifid, thicker (2-2.8 and begin segment VI, bifid, with very pm wide) nodulus reduced distal teeth. with distinct at about 1/3 from distal end. Distal ends of setae of anterior bundles strongly curved. teethof bifid setae of II and III minute Distribution and habitat. - Known from Asia, Af- Upper and difficult to but about halfthe rica, N. and S. America. Not previously known to see, reaching length of lower teeth in middle inhabit subterranean habitats. region of body. Setal length from 64-80 in ranging pm segment II to 80-100 pm in middle region of body. Except for anterior bundles, the thinner, single pointed setae seem to Family: PHREODRILIDAE be than bifid but latter longer setae, extending more Subfamily: Phreodrilinae into coelomic Ventral setae absent Antarctodrilus arabicus deeply cavity.