Euryhaliotrema atlantica, Kritsky & Boeger, 2002

Kritsky, Delane C. & Boeger, Walter A., 2002, 41: New and previously described species of Dactylogyridae (Platyhelminthes) from the gills of marine and freshwater perciform fishes (Teleostei) with proposal of a new genus and a hypothesis on phylogeny, Zoosystema 24 (1), pp. 7-40 : 21-24

Euryhaliotrema atlantica n. sp.

( Fig. 7 ) TYPE SPECIMENS. — Holotype ( INPA 412 ); 13 paratypes ( USNPC 91423 , 91424 , HWML 16430 , INPA 413 a-e, MNHN 27 HG Tg 159).

ETYMOLOGY. — The specific name is derived from Greek (atlantikon = the Atlantic [Ocean]).

TYPE HOST AND LOCALITY. — Gills of Paralonchurus brasiliensis (Sciaenidae) : Baía de Guaratuba, Guaratuba, Paraná, Brazil, 30°50’S, 48°28’W, 15.VII.1996.

MATERIAL EXAMINED. — Paralonchurus brasiliensis (Sciaenidae) : five voucher specimens, Atlantic Ocean off Rio Grande, Rio Grande do Sul, Brazil, 32°00’S, 51°48’W, 4.III.1996 ( USNPC 91425).

DESCRIPTION

Body 614 (582-664; n = 6) long, slender, fusiform; greatest width 108 (94-122; n = 6) usually at level of testis. Cephalic region broad; cephalic lobes moderately developed; small spike frequently protruding from second pair of head organs. Eyes subequal, equidistant, infrequently dissociated; accessory granules common in cephalic, anterior trunk regions. Pharynx subspherical to ovate, 43 (36-46; n = 6) in diameter. Peduncle elongate; haptor subhexagonal, 88 (77-98; n = 6) wide, 65 (57-68; n = 5) long. Anchors similar; each with poorly differentiated short roots, evenly curved short shaft, point extending past level of tip of superficial root; ventral anchor 30 (28-32; n = 5) long, base 17 (16-18; n = 4) wide; dorsal anchor 27 (26-29; n = 5) long, base 14 (12-15; n = 4) wide. Ventral bar 42 (40-44; n = 5) long, slightly bent posteriorly near midlength, with slightly expanded ends, small posterior shield, delicate medioanterior cup-shaped projection; dorsal bar 37 (31-41; n = 5) long, V-shaped, with knob-like ends. Hook 13-14 (n = 10) long, with uniform shank; FH loop about shank length. Copulatory organ a coil of about two and a half counterclockwise rings, 109 (100-115; n = 3) long, proximal ring diameter 15 (14-17; n = 8). Accessory piece 26 (24-29; n = 3) long, comprising variable sheath along distal shaft of copulatory organ, with posteriorly directed branch originating near midlength; articulation process attached to base of copulatory organ. Testis 78 (n = 1) long, 31 (n = 1) wide, ovate; seminal vesicle pyriform; 1 prostatic reservoir. Germarium pyriform to elongate ovate, 67 (64-78; n = 4) long, 30 (25-38; n = 4) wide; oviduct, ootype not observed; uterus delicate, ventral. Vaginal aperture on fleshy bulb protruding from right side of body; vaginal canal with distal loop; seminal receptacle anterior to germarium, large, ovate. Vitellaria dense.

REMARKS

This species closely resembles Euryhaliotrema paralonchuri n. comb., from which it differs in having smaller and more delicate haptoral sclerites and copulatory complex. The vaginal tube in E. atlantica n. gen., n. sp. is narrow and lightly sclerotized, while it has a much larger diameter and apparently lacks sclerotization in E. paralonchuri n. gen., n. sp.

Figures

FIG. 7. — Euryhaliotrema atlantica n. gen., n. sp.; A, whole mount (composite, ventral view); B, vagina (ventral view); C, copulatory complex (ventral view); D, ventral bar; E, dorsal bar; F, ventral anchor; G, hook; H, dorsal anchor. Scale bars: A, 200 µm; B-H, 25 µm.