116 Vankara et al.fleshy, with a rugose dorsal surface and a smooth genus of the family. Thatcher (1961) erected thisventral region. Dorsal surface of scolex bears two genus with C. thatcheri as its type-species fromparallel rows of fleshy papilli<strong>for</strong>m proliferations on Carcharhinus limbatus Val, 1840 in the coastal watersthe margins of upper surface of the scolex. Scolex of Mississippi and Louisiana. <strong>The</strong> genus isperpendicular with a v-shaped bent in the centre and characterized by the presence of the perpendicularthe two arms being drawn into thin, long, narrow and head and hence the name is derived from greek wordsslender ribbon like structures. <strong>The</strong>se ribbon like “Katheto” and “Kephalos”. At that time, Thatcherstructures are thin and delicate and are difficult <strong>for</strong> considered it as Pillersium owenium Southwell, 1927separation from tissues during collection. Accessory because of T-shaped scolex but Dailey and Overstreethooks or suckers not seen. Each arm of the scolex (1973) re-examined Thatcher's original material andmeasures 2.50–2.63 from the base and the ribbon named it as Cathetocephalus thatcheri, which was themeasures 2.9–3 long. Neck thick, long and measures type and the only species in the genus and erected the5–6.57 x 0.16–0.18. Strobila comprises 55–110 family Cathetocephalidae <strong>for</strong> it. However, in hisproglottids. Proglottids 3–4 times longer than broad. description, he failed to record the number of testes.Immature proglottids measure 0.58–1.21 x 0.29–0.47. Later, Watson and Thorson (1976) redescribed thisMature region starts <strong>for</strong>m 0.26–0.83 behind the neck. species from Lake Nicaragua and recorded the numberMature proglottids measure 2.05–4.08 x 0.32–0.58. of testes to be 300-400. Schmidt (1986) alsoGravid proglottids not obtained. Testes small, recognized a fourth family, the Cathetocephalidae148–280 in number, spherical measuring 0.03–0.08 in Dailey and Overstreet, 1973, within the Tetraphyllideadiameter. Testes pre-ovarian, filling the full length in in addition to the Onchobothriidae, Phyllobothriidaemedullary region, but not reaching upto the anterior and Triloculariidae. Euzet (1994), in a most recent andmargin of the proglottid. A space is left in the anterior comprehensive treatment of the group, recognisedmost region of the proglottid characteristically. Cirrus eight families of tetraphyllideans of whichsac large, pear-shaped and measures 0.11–0.34 x Cathetocephalidae was one among them.0.20–0.55. Cirrus unarmed measuring 0.08–0.10 inlength. Genital pores irregularly alternate and openSchmidt and Beveridge (1990) after a long span ofslightly posterior to the mid margin of the proglottid.time described a second species, C. australis of theVagina opens anterior to the cirrus and emptying intofamily Cathetocephalidae from the spiral intestine ofcommon genital atrium. Ovary large, with two wingC. amblyrhynchoides from Australian waters. Smallshaped lobes, posterior in position. Each lobescolex, craspedote proglottids, small ovarian lobes,measures 0.2–0.72 x 0.11–0.42. Vitellaria follicular,less number of testes and follicular vitellaria,lateral in position extending in the entire margin of thecharacterize this species. Pramanik and Manna (2006)proglottid in cortical region. Uterus tubular, originatesdescribed C. limbatus from the spiral valves offrom ovarian isthmus and extends anteriorly.Carcharhinus limbatus from India, which ischaracterized in having scolex with four suckers, ovalHost: Carcharhinus leucas Valenciennes, 1839 cirrus pouch, U-shaped ovary and follicular vitellaria.Habitat: Spiral valve of the intestineLocation: Visakhapatnam coast, Andhra Pradesh,IndiaNo. of specimens: FourDeposition of specimens: Holotype and Paratypesdeposited in the <strong>Parasitology</strong> Laboratory, Departmentof Zoology, Andhra University, Visakhapatnam.Etymology: Named after the species name of the hostfish.DISCUSSIONCathetocephalidae is a small family of the orderTetraphyllidea with Cathetocephalus as the only<strong>The</strong> present species shows some resemblances anddifferences with these three species. It comes closer toC. thatcheri in not having suckers but differs in manycharacters like number of testes, number ofproglottids, craspedote strobila and shape of scolex. Itresembles C. australis in having follicular vitellariaand number of testes but differs in the shape of scolex,number of proglottids, position of genital opening, andnature of strobila. It comes closer to C. limbatus inhaving follicular vitellaria, acraspedote strobila butdiffers in the shape of scolex and number of testes. <strong>The</strong>present parasites characteristically differ from allthese three species in having an unique scolex with anupward bent in the centre, giving v-shape to the scolexwith its two arms drawn into a narrow, slender ribbon
C. leucas, a new species117Table I. Comparison of present new species of Cathetocephalus with other related species of the genusC.thatcheri C.australis C.limbatus PresentDailey et Overstreet, 1973 Schmidt & Beveridge, 1990 Pramanik & Manna,2006 new species1. Host Carcharhinus leucas C.amblyrhynchoides Carcharhinus limbatus Carcharhinus leucas( Val, 1839) (Whitley, 1934) ( Val, 1840) ( Val, 1839)2. Size 10.1-10.5 cm 5 cm 4.80 cm 7-8 cm3. No. of proglottids 228-325, Slightly craspedote 94-98, slightly acraspedote 55-110, SlightlySlightly craspedote acraspedote4. Size of scolex 4-10 1.12-2.9 1.7 with four suckers 2.5-2.63 x 0.5-0.7, suckers notseen5. Width at broader 0.55-1.5 0.5-0.96 -Surface6. Neck 0.55-1.5 0.21-0.44 2.26 x 0.3 5.0-6.57 x 0.16-0.187. Mature proglottids 2.9-4.1 x 0.86-1.21 0.92-1.68 x 0.77-1.60 1.71 x 0.54 2.05-4.08 x 0.32-0.588. Gravid proglottids 5.5 x 1.0 1.68-2.98 x 1.38-1.76 - -9. Testes 300-500, not reaching 125-205, occupies anterior 132-134, reaching upto 148-280, not reaching uptoanterior margin of margin of proglottid anterior margin of anterior margin of proglottid.proglottid proglottid10. Cirrus sac 0.53-0.59 x 0.25-0.34 0.30-0.63 x 0.16-0.32 0.3 x 0.2 0.11-0.34 x 0.20-0.5511. Genital opening Lateral, irregularly Lateral, irregularly alternate, mid-portion of segment lateral, irregularly alternate,alternate, slightly posterior mid region of proglottid slightly posterior to mid regionmid region of proglottid of proglottid12. Ovary dumb-bell shaped U-shaped, 0.45 x 0.2 Winged, 0.2-0.72 x 0.11-0.420.99-1.13 x 0.34-0.50 0.20-0.40 x 0.40-0.8413. Vitellaria Granular, not extending Follicular, <strong>for</strong>ming Follicular, 2-3 rows Follicularentire length of proglottid a sleeve around vitellaria* Note: Measurements are given in millimeters, unless otherwise stated.
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