Dactylogyrus acanthobramae Paperna, 1961 is redescribed and its relationship with other species of this genus is discussed

Mashego, S.N.

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S. Afr. J. ZooJ. 1989,24(3) Short Communications Redescription of Dactylogyrus acanthobramae Paperna, 1961 (Dactylogyridae: Monogenea) S.N. Mashego University of the North, Private Bag X11 06, Sovenga, 0727 Republic of South Africa Received 15 June 1988; accepted 11 November 1988 Dactylogyrus acanthobramae Papema, 1961 is redescribed and its relationship with other species of this genus is discussed. 'n Herbeskrywing, met aanvullende morfologiese gegewens van Dactylogyrus acanthobramae Papema, 1961 word ge-gee. Die Dactylogyrus-spesieverwantskappe met betrekking tot hierdie vorm word bespreek. Monogenea parasitic on freshwater fish from Lake Kinnereth (Galilee) were collected and studied by Paperna (1960, 1961, 1964). Among other species he described Dactylogyrus acanthobramae Paperna, 1961, from Mirogrex terraesanctae terraesanctae collected on the western shore of the lake. During a survey of monogenean parasites of fish from this lake in October 1980, additional specimens of D. acanthobramae were collected. On examination these parasites were found to possess an additional bar not described by Paperna (1961). The type specimens of D. acanthobramae were obtained and re-examined resulting in the present redescription. Fish hosts were collected from the western shore of Lake Kinnereth using gill and beach seine nets. Gills were removed from the fish hosts as quickly as possible and fixed in 2% formalin for 30 min. This allows for the parasites to die relaxed because the solution is not strong enough to kill them immediately. The strength of the solution was then increased to 4%. The gills and sediments were later checked for parasites. Monogenea were cleared and embedded in glycerine jelly under slight pressure. Measurements were taken according to the scheme of Papema (1959) and are given in micrometres. Description (based on 7 specimens) Figures 1-6 Small, slender, delicate worms, 219-366 long, 38--80 wide. Opisthaptor small, not clearly delimited from body. Anchors 46-55 long, inner root 1~16, outer root 5-9, shaft 29-31, tip 14-16. First bar is T-shaped with a slit along the midline of the vertical arm, latter 1~ 15 long, 9-14 wide at the base, cross arm length 16-23. Second bar elongated and sligthly curved with a constriction at its center and sligthly thickened edges, 231 JO~", Figure 1-6 Sclerotinoid structures of Dactylogyrus acantho-bramae Paperna, 1961. 1. First bar; 2. Second bar; 3. Anchors; 4. Hooklets; S. Vagina; 6. Copulatory organ. 2~29 long, 5-6 thick. Hooklets with thick handle and slender shaft and spike, handles about half of hooklet's entire length; central hooklets (16-19) are smaller than marginal hooklets (25-27 long). The copulatory organ consists of an ejaculatory duct which originates from a large oval funnel and continues as a long winding tube, 25-34 long, and an accessory piece, 15-16 long, consisting of a plate attached to the funnel ofthe ejaculator. The sclerotized vagina is coiled, 6-8 long, with projections at the proximal end. Host: Mirogrex terraesanctae terraesanctae (Steinitz, 1952). Locality: Western shore of Lake Kinnereth. Discussion The anchors of the material collected during this survey are larger (46-55 long) than those of the type specimens (25-39) but the other measurements fall within the range given in the original description. Although the first bar is present in the type specimens, it appears Paperna (1961) overlooked it because it was neither drawn nor decribed. He suggested that in having one bar D. acanthobramae was similar to a group of Dactylogyrus species described by Gussev (1955) from the gills of Cyprinus carpio haemopterus from the Amur River System in south-east U.S.S.R. These species, i.e. D. achmerowi Gussev, 1955, D. anchoratus Gussev, 1955, D. extensus Mueller and Van Cleave, 1932, D. faldformes Akhmerov, 1952, D. formosus Kulwiec, 1927, D. minutus Kulwiec, 1927, D. mol/is (Wedl, 1857) and D. vastator Nybelin, 1924, are characterized by a single bar which is very similar to the second bar of D. acanthobramae. However, the presence and the structure of the two bars of D. acanthobramae as well as the shape of its copulatory organ is evidence of a close relationship to another group of Dactylogyrus species. These are D. difformis Wagener, 1857, D. fratemus Wagener, 1909, D. minor Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2010). 232 Wagener, 1857, D. nanus Dogiel and Bychowsky, 1934 and D. parvus Wagener, 1909, associated with Palaeoarctic cyprinids of the subfamily Leuciscinae, namely species of the genera Albumus, BUcca, Leuciscus, Rutilus and Scardinius. The other species found on Mirogrex terraesanctae terraesanctae in Lake Kinnereth, namely Dactylogyrus sphyma Linstow, 1878, is also a Palaeoarctic species associated with fish of the above mentioned genera. This finding confirms affinity of the Monogenea parasitic on M. terraesanctae terraesanctae, with Palaeoarctic monogeneans associated with the subfamily Leuciscinae. Acknowledgements This study was done within the framework of the CSIR-NCRD exchange programme at the H. Steinitz Marine Biology laboratory of the Hebrew University of Jerusalem and Lake Kinnereth Research Laboratory, Israel. I wish to thank Dr Han Paperna of the former Laboratory and Dr Moshe Gophen of the latter laboratory for the provision of facilities and assistance in identifying the parasites and fish hosts. References GUSSEV, A.V. 1955. Monogenetic trematodes of fishes of the Amur River System. Trud. Zool. Inst. AN SSSR. 19: 171-398. PAPERNA, I. 1959. Studies on monogenetic trematodes in Israel. 1. Three species of monogenetic trematodes of reared carp. Bamidgeh, Bull. Fish. Cult. Israel. 2: 51-{)7. PAPERNA, I. 1960. Studies on monogenetic trematodes in Israel. 2. Monogenetic trematodes of chichlids. Bamidgeh, Bull. Fish. Cult. Israel. 12: 20-30 PAPERNA, I. 1961. Studies on monogenetic trematodes in Israel. 3. Monogenetic trematodes of the Cyprinidae and Claridae of the Lake Galilee. Bamidgeh, Bull. Fish. Cult. Israel. 13: 14-29. P APERNA, I. 1964. Parasitic helminths from inland water fishes in Israel. Israel J. Zool. 13: 1-20. S.-Afr. Tydskr. Dierk. 1989,24(3) The diet of barn owls at a roost near Grahamstown J.O. Wirminghaus Department of Zoology and Entomology, Rhodes University, Grahamstown, Republic of South Africa· Received 15 June 1988; accepted I December 1988 Barn owl Tyto alba pellets were collected over a period of 13 months from a roost near Grahamstown. Twelve species of small mammals and two bird species were found in the pellets. Mastomys natalensis and Mus minutoides were most numerous in the diet of the owls toward the end of winter whilst in summer Otomys irroratus and O. saundersae formed most of the prey remains. Onverteerde, pilvormige kosreste van nonnetjie-uile Tyto alba is oor 'n tydperk van 13 maande by 'n slaapplek naby Grahamstad versamel. Twaalf kleinsoogdierspesies en twee voelspesies is in die kosreste gevind. Mastomys natalensis en Mus minutoides was die mees algemene voedselsoorte van die uile teen die einde van die winter terwyl Otomys irroratus en 0. saundersae die meerderheid van die prooireste gedurende die somer gevorm het. 'Present address: Department of Zoology and Entomology, University of Natal, P.O. Box 375, Pietermaritzburg, 3200 Republic of South Africa Analyses of pellets of birds of prey, particularly of bam owls T. alba in southern Africa have yielded some useful distributional data on small mammals (NeI1969; Vernon 1972; Dean 1973; Skinner, Lindeque, van Aarde & Dieckmann 1980; Tilson & Le Roux 1983). Most of the studies are based on a single collection of pellets from a roost, from which only distributional information and a list of prey items can be obtained. Perrin (1982) compared his analysis of a single collection of pellets to the results of trapping in adjacent habitats and was able to draw some conclusions on prey selection by the owls. I collected pellets at roughly monthly intervals over a period of 13 months (1986/87) from a barn owl roost situated in a small recess of a cliff on the farm Thornkloof (33°14'S / 26°19'E) 15 km north-west of Grahamstown in the eastern Cape. During my first visit to the site in April 1986 all skeletal debris from old pellets was cleared from below the roost, so that only pellets regurgitated between sampling periods were collected. The vegetation surrounding Thornkloof for several kilometres is karroid and similar to Acocks's (1975) Fish River Scrub (veld type 23). During the study the area was still in the grip of a drought. Each pellet was soaked in water before being dissected and all the skulls of vertebrates were retained and identified using Coetzee (1972), De Graaff (1981), and Smithers (1983). Some doubtful material was sent to the Kaffrarian Museum for identification. Mean masses of vertebrates were obtained from De Graaff (1981), Smithers (1983) and Maclean (1985). The numbers and the mean total biomass of each prey species in the pellets is summarized in Table 1. Small Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2010). 

Redescription of Dactylogyrus acanthobramae Paperna, 1961 (Dactylogyridae: Monogenea)

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Redescription of Dactylogyrus acanthobramae Paperna, 1961 (Dactylogyridae: Monogenea)

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