Caballerocotyla llewelyni, Kohn, Anna & Justo, Márcia C. N., 2006

Kohn, Anna & Justo, Márcia C. N., 2006, Caballerocotyla llewelyni n. sp. and Caballerocotyla neothunni (Yamaguti, 1968) (Monogenea; Capsalidae) parasites of Brazilian tunas (Scombridae), Zootaxa 1139, pp. 19-26 : 20

Caballerocotyla llewelyni n. sp. ( Figs. 1–6 )

Type host: Katsuwonus pelamis (Linneus, 1758) , Scombridae , the skipjack tuna.

Site: Gills.

Type locality: Atlantic Ocean, Brazil, Rio de Janeiro State.

Prevalence: Two specimens in one out of 16 fish examined.

Deposition of specimens: CHIOC, nº 36611 A (holotype) and n o 36611 B (paratype).

Etymology: The new species is named in honor of the late Professor Jack Llewelyn in recognition of his many contributions to studies on Monogenea.

Description

Based on two adult specimens. Body flattened dorso­ventrally, approximately elliptical in outline, lacking dorso­marginal spines or papillae, measuring 3.8–4.1mm in length excluding haptor, by 2.5–2.8mm in maximum width. Haptor circular, sessile, divided by seven septa in seven marginal and one central areola “keyhole­shaped”, surrounded by delicate plicate marginal membrane, and with uniformly distributed cuticular papillae on ventral surface; haptor 0.35–0.59 mm long by 0.47–0.55mm wide. One pair of nearly straight anchors, 127–130 long and 14 marginal hooklets present. Anterior end of body with pair of cephalic lobes and a pair of sucker­like attachment organs 290–330 long by 400–440 wide. Two pairs of small eye spots. Mouth opening ventrally at anterior end of pharynx. Pharynx muscular, composed of two unequal bulbs, the posterior smaller than anterior, with papillae distributed over inner surface, measuring 610 in total length, 400 by 550 in anterior bulb and 360 by 310 in posterior one. Testes round, 38–43 in number, intercecal, with 129–145 long by 132–152 wide. Few Gotos glands scattered among testes. Vas deferens passing between seminal receptacle and vitelline reservoir, turning back on itself, entering cirrus pouch near its base. Cirrus pouch claviform, unarmed. Genital pore to left of pharynx at level of its anterior part. Ovary subglobular, preequatorial, median, 250–320 by 260–420. Ootype with one tetrahedric egg present in one of the specimens studied, 100 x 75, with 4 filaments, anterior filament 17 long and posterior 40 long; uterus opening into genital atrium. Vagina opening ventrally, posterior to genital pore. Seminal receptacle round, 140–175 by 130–155. Vitelline follicles small, in the caecal and diverticular, testicular and cephalic regions. Vitelline reservoir 130 by 240, immediately preovarian.

Figures

FIGURES 1 – 6. Caballerocotyla llewelyni n. sp. 1. Holotype ventral view. 2. Anchors. 3. Ovary and terminal genitalia of paratype. 4. Light micrograph of total worm. 5. Light micrograph of egg with four filaments. 6. Confocal scanning light micrograph, haptor with papillae and marginal membrane. Scales­bars: 1, 1 mm; 2, 0.05 mm; 3, 0.5 mm.