Eutetrarhynchus platycephali

Haseli, Mohammad, Malek, Masoumeh & Palm, Harry Wilhelm, 2010, Trypanorhynch cestodes of elasmobranchs from the Persian Gulf, Zootaxa 2492, pp. 28-48 : 35-36

Eutetrarhynchus platycephali

( Fig. 2 )

(N=5): SL=3321 (2731–4058), SW at pbo=420 (270–673), SW at pb=376 (362-398), pbo=423 (320–497), TW=65 (57–72) basal, TW=71 (65–76) metabasal. TL=1953 (1811–2166), pv=1890 (1538–2471), TSW=71 (57–80), pb=1430 (1308–1541), ppb=18 (0–50), BL=1396 (1192–1512), BW=166 (142–199), BR=8.4, SP=1:4.5:1.3. Metabasal armature heteroacanthous typical, homeomorphous, in ascending half spirals of hollow hooks; metabasal hooks, L=13 (10–17), B=5 (4–8). Characteristic basal armature absent. Basal hooks on bothrial surface, L=10 (9–11), B=5 (4–8). Basal hooks on antibothrial surface, L=10 (9–12). Single enlarged uncinate hook on 8th row on external surface, L=19, B=13. Long worm, L=21369 (10712–30989), with 37–65 segments. Strobila acraspedote. Cirrus unarmed, cirrus sac lateral, postequatorial, L=231 (178– 284), W=163 (114–213), Genital pore marginal. Mature segment longer than wide, L=1208, W=875. Testes preovarian, L=29 (17–48), W=45 (27–67). Ovary bilobed from dorsoventral view and posterior, ovarian lobe, L=264 (135–391), W=161 (121–178). Uterus median, tubular, reaching anterior extremity.

Remarks: This is the first description of the adult worms of Eutetrarhynchus platycephali from the intestine of Himantura sp., Rhinobatos cf. punctifer and Pastinachus cf. sephen . The morphological characters of the scolex and armature correspond to those presented by Palm (2004), who recorded the plerocerci from the gills of an unidentified Platycephalidae from Pelabuhan Ratu, Indonesia. Beside the characteristic scolex shape and measurements, the single enlarged uncinate hook in the 8th row on external tentacle surface was clearly evident. The specimens from the Persian Gulf are slightly smaller than those from Indonesia. The occurrence of this species in the Gulf extends the known range of distribution from Indonesian waters to the north-western Indian Ocean.

Figures

FIGURE 2 a – f. Eutetrarhynchus platycephali. a. Scolex. b. External surface, basal armature. c. Internal surface, metabasal armature. d. Bothrial surface, metabasal armature. e. External surface, metabasal armature. f. Mature segment. Fig. 2 g. Eutetrarhynchus sp. Scale bars: a, 1000; b – e, 10; f, 500; g, 100.