Euryhaliotrema, 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 : 10-11

Genus Euryhaliotrema n. gen.

TYPE SPECIES. — Euryhaliotrema chaoi n. gen., n. sp. from Plagioscion sp. and P. squamosissimus (Heckel, 1840) (Sciaenidae) .

SPECIES INCLUDED. — Euryhaliotrema atlantica n. gen., n. sp. from Paralonchurus brasiliensis (Steindachner, 1875) (Sciaenidae) ; Euryhaliotrema bychowskyi ( Obodnikova, 1976) n. comb. from Hapalogenys mucronatus (Eydoux & Souleyet, 1850) (Haemulidae) ; Euryhaliotrema carbunculus ( Hargis, 1955) n. comb. from Lagodon rhomboides (Linnaeus, 1766) (Sparidae) ; Euryhaliotrema chrysotaeniae ( Young, 1968) n. comb. from Lutjanus carponotatus (Richardson, 1842) (senior synonym of Lutjanus chrysotaenia [Bleeker, 1851]) ( Lutjanidae ); Euryhaliotrema fastigatum ( Zhukov, 1976) n. comb. * from Lutjanus apodus (Walbaum, 1792) and Lutjanus jocu (Bloch & Schneider, 1801) (Lutjanidae) ; Euryhaliotrema johni ( Tripathi, 1959) n. comb. from Lutjanus johnii (Bloch, 1792) and Lutjanus fulviflammus (Forsskål, 1775) (Lutjanidae) ; Euryhaliotrema longibaculum ( Zhukov, 1976) n. comb. from Lutjanus mahogoni (Cuvier, 1828) and Lutjanus synagris (Linnaeus, 1758) (Lutjanidae) ; Euryhaliotrema lovejoyi n. gen., n. sp. from Plagioscion squamosissimus and Plagioscion sp. (Sciaenidae) ; Euryhaliotrema lutiani ( Yamaguti, 1953) n. comb. from Lutjanus sp. (Lutjanidae) ; Euryhaliotrema monacanthus n. gen., n. sp. from Plagioscion squamosissimus and Plagioscion sp. (Sciaenidae) ; Euryhaliotrema paracanthi ( Zhukov, 1976) n. comb. * from Lutjanus apodus (Lutjanidae) ; Euryhaliotrema paralonchuri ( Lugue & Iannacone, 1989) n. comb. from Paralonchurus peruanus (Steindachner, 1875) (Sciaenidae) ; Euryhaliotrema potamocetes n. gen., n. sp. from Plagioscion squamosissimus and Plagioscion sp. (Sciaenidae) ; Euryhaliotrema sagmatum n. gen., n. sp. from Umbrina xanti Gill, 1862 (Sciaenidae) ; Euryhaliotrema succedaneus n. gen., n. sp. from Plagioscion squamosissimus and Plagioscion sp. (Sciaenidae) ; Euryhaliotrema thatcheri n. gen., n. sp. from Plagioscion squamosissimus and Plagioscion sp. (Sciaenidae) ; Euryhaliotrema torquecirrus ( Zhukov, 1976) n. comb. from Lutjanus synagris and Ocyurus chrysurus (Bloch, 1791) (Lutjanidae) ; Euryhaliotrema tubocirrus ( Zhukov, 1976) n. comb. from Lutjanus analis (Cuvier, 1828) , L. apodus , Lutjanus cyanopterus (Cuvier, 1828) , L. synagris and Rhomboplites aurorubens (Cuvier, 1829) (Lutjanidae) . Species identified by an asterisk are transferred to Euryhaliotrema n. gen. without benefit of the present authors’ examination of type or voucher specimens.

ETYMOLOGY. — The generic name is from Greek (eury = wide, broad + hali/o = sea, salt) appended to the commonly used ending -trema. The name refers to the broad saline conditions (freshwater to marine) in which members of the genus occur.

DIAGNOSIS. — Body fusiform or flattened dorsoventrally, comprising cephalic region, trunk, peduncle, haptor. Tegument smooth. Two terminal, two bilateral cephalic lobes; three pairs of bilateral head organs; cephalic glands unicellular, lateral or posterolateral to pharynx. Eyes 4; granules small, ovate. Mouth subterminal, midventral; pharynx comprising muscular, glandular bulb; esophagus short; intestinal ceca 2, confluent posterior to gonads, lacking diverticula. Common genital pore midventral near level of intestinal bifurcation. Gonads intercecal, tandem or slightly overlapping; germarium pretesticular. Vas deferens looping left intestinal cecum; seminal vesicle a simple dilation of vas deferens; one or two prostatic reservoirs. Copulatory complex comprising tubular copulatory organ coiled or meandering, accessory piece; base of copulatory organ expanded to form bulb. Accessory piece serving as guide for distal portion of copulatory organ, with or without articulation process attached to base of copulatory organ. Seminal receptacle pregermarial; vaginal aperture dextral, marginal or submarginal; vagina sclerotized. Vitellaria in trunk, absent from regions of other reproductive organs. Haptor globose, with dorsal, ventral anchor/bar complexes (one species lacking dorsal complex), seven pairs of similar hooks. Hook distribution as described by Mizelle (1936); hook with upright acute thumb, slender shank comprised of one subunit. Bars straight to V-shaped. Parasites of gills of marine and freshwater teleosts.

REMARKS

Euryhaliotrema n. gen. is distinguished by one synapomorphy (bulbous base on the copulatory organ) and is further diagnosed by dactylogyrids with the combined presence of: 1) tandem or slightly overlapping gonads (germarium pretesticular); 2) the vas deferens looping the left intestinal cecum; 3) the copulatory complex comprising a coiled or meandering tubular copulatory organ and an accessory piece; 4) a dextral (marginal or submarginal) vaginal aperture; 5) ventral and dorsal anchor/bar complexes (dorsal complex absent in E. monacanthus n. gen., n. sp.); and 6) 14 hooks, each with an upright acute thumb and a slender shank composed on one subunit. The new genus includes seven new species and 12 species previously included in Haliotrema or Pseudohaliotrema Yamaguti, 1953 . Presence of a bulbous base of the copulatory organ distinguishes Euryhaliotrema n. gen. from these latter genera.