Whittingtonocotyle, Santos Neto, João F., Rodrigues, Allan R. O. & Domingues, Marcus V., 2015

Santos Neto, João F., Rodrigues, Allan R. O. & Domingues, Marcus V., 2015, Proposal of Whittingtonocotyle n. gen. (Dactylogyroidea: Dactylogyridae), with the description of two new species from the gills of Hoplerythrinus unitaeniatus (Characiformes: Erythrinidae) in Brazil, Zootaxa 3937 (1), pp. 191-200 : 192-193

Whittingtonocotyle n. gen.

Type species. Whittingtonocotyle caetei n. gen. n. sp. from Hoplerythrinus unitaeniatus (Agassiz) .

Site. Gills.

Type locality. Caeté River (North/Northeast Atlantic Basin; Caeté, Gurupi, Turiaçu sub-basin), municipality of Augusto Corrêa, Pará State, Brazil (1°3’58.21” S 46°40’3.65”W) collected in October 2013.

Other species. Whittingtonocotyle jeju n. gen. n. sp.

Other localities. Whittingtonocotyle caetei n. gen. n. sp. from Hoplerythrinus unitaeniatus from Guamá River (North/Northeast Atlantic Basin; Meruu, Acará, Guamá sub-basin), municipality of Irituia, Pará State, Brazil (01°51’59.8” S, 47°24’17.2”W) collected in July 2014, Whittingtonocotyle jeju n. gen. n. sp. from Hoplerythrinus unitaeniatus from Caeté River, municipality of Augusto Corrêa, Pará State, Brazil (1°3’58.21” S 46°40’3.65”W) collected in October 2013; and Guamá River, municipality of Irituia, Pará State, Brazil (01°51’59.8” S, 47°24’17.2”W) collected in July 2014.

Etymology. The genus name is in honor of the late Dr. Ian D. Whittington, the South Australian Museum, in recognition of his valuable work on the Monogenoidea. Dr. Whittington passed away prematurely on 26th October, 2014, after a long battle with cancer.

Diagnosis. Body divisible into cephalic region, trunk, haptor. Tegument thin, smooth. Cephalic region with terminal ventral cephalic lobe poorly developed or absent. Bilateral pair of head organs opening subterminal to tip of cephalic lobes; cephalic glands lateral or postero-lateral to pharynx. Eyes present (2 pairs); granules elongate. Mouth subterminal, midventral; pharynx muscular, glandular; oesophagus short. Intestinal caeca 2, confluent posteriorly to gonads, lacking diverticula. Genital pore mid-ventral near level of cecal bifurcation. Genital atrium muscular. Gonads tandem or testis post-germarial; testis dorsal to germarium. Vas deferens looping left intestinal cecum; seminal vesicle sigmoid, looping dorso-ventrally before entering into the male copulatory organ. One prostatic reservoir, saccate; separated into two or three zones; one or two terminal areas densely stained. Copulatory complex comprising male copulatory organ, accessory piece; male copulatory organ sclerotized, spiral, clockwise; accessory piece sclerotized, non-articulated with the male copulatory organ. Vagina single; vaginal aperture dextro-dorsal, marginal, opening anteriorly or at mid-level of the trunk; vaginal vestibule muscular; vaginal canal heavily sclerotized, sigmoid or coiled. Seminal receptacle present, anterior to germarium. Egg ovate with short filament. Vitellaria well developed, coextensive with caeca. Haptor armed with, 14 hooks (7 pairs) with ancyrocephaline distribution ( Mizelle 1936). Pair of ventral and dorsal anchors; anchors without well-defined roots. Ventral and dorsal bar; dorsal bar with anteromedial process. Parasites of gills of erythrinid fishes.

Remarks. Whittingtonocotyle n. gen. is characterized by species possessing: (1) male copulatory organ sclerotized, spiral, clockwise, non-articulated with accessory piece; (2) prostatic reservoir separated into two/three zones with one or two terminal areas densely stained with Gomori’s trichrome; (3) vaginal aperture dextrodorsal; (4) anchors without well-defined roots; and (5) dorsal bar with anteromedial protuberance. Whittingtonocotyle n. gen. resembles Unilatus Mizelle & Kritsky, 1967, by having species with a male copulatory organ spiral, corkscrew like, non-articulated with accessory piece. The new genus differs from Unilatus by lacking small bulb on the distal medial portion of the male copulatory organ, by having dorsal and ventral anchor/bar complexes (anchor/bar complexes in the dorsal area of the haptor in Unilatus), and by the vagina opening dorsally on the right side (ventral, medial in Unilatus).