Tetrancistrum suezicum (Paperna, 1972) Kritsky & Galli & Tingbao, 2007

Kritsky, Delane C., Galli, Paolo & Tingbao, Yang, 2007, Dactylogyrids (Monogenoidea) parasitizing the gills of spinefoots (Teleostei, Siganidae): revision of Tetrancistrum Goto and Kikuchi, 1917, with descriptions of two new species from Siganus spp. of the Red Sea and Celebes, Journal of Natural History 41 (25 - 28), pp. 1513-1551 : 1529-1531

Tetrancistrum suezicum (Paperna, 1972) comb. n.

( Figures 28–34 ) Synonyms: Pseudohaliotrematoides polymorphus suezicus Paperna, 1972 ; P. suezicus Paperna,

1972; Pseudohaliotrematodides polymorphus suezicus of Ktari and Ktari (1974) (lapsus);

Pseudohaliotrematoides suezicus Paperna, 1972 .

Redescription. Based on six voucher specimens from S. riυulatus in the Ras Mohammed National Park. Body foliiform; trunk broad; cephalic region narrow; peduncle tapered posteriorly; greatest body width near body midlength. Cephalic lobes moderately to well developed; each head organ comprises several groupings of terminations of cephalic-gland ducts; large bilateral groups of cephalic glands posterolateral to pharynx. Two pairs of eyespots in two of six specimens; posterior pair larger and slightly farther apart than anterior pair; random accumulations of chromatic granules present or absent; minute subovate granules scattered throughout cephalic region. Pharynx ovate; intestinal caeca lacking diverticula. Testis subspherical; vas deferens and seminal vesicle not observed; prostatic reservoirs inconspicuous. Copulatory complex comprises articulated MCO and accessory piece. MCO a J-shaped tube with short anterior flange and elongate posterior flange terminally frayed; accessory piece rod-shaped, with doubly recurved tip. Germarium comparatively large, conical to subcylindrical; ootype receives vaginal duct and bilateral vitelline ducts; uterus midventral, extends ventrally to genital pore along body midline. Vaginal pore at level of copulatory complex; vaginal vestibule variable, lightly sclerotized; meandering vaginal duct extending to ootype. Vitellarium dense. Haptoral hooks absent; few FH loops occasionally retained in adult. Ventral and dorsal anchors typical; superficial root of ventral anchor noticeably longer than deep root. Ventral bar straight, with ends recurved posteriorly to posterior margin of bar; dorsal bar broadly V-shaped, with slight terminal expansions.

Measurements. Body 1306 (n 51) long; greatest width 330 (301–359; n 52). Haptor 85 (n 51) long, 72 (n 51) wide. Pharynx 55 (47–64; n 52) wide. Copulatory complex 87 (77– 100; n 55) long. Ventral anchor 80 (70–84; n 54) long; base 34 (32–36; n 53) wide. Dorsal anchor 81 (72–89; n 54) long; base 25 (24–27; n 53) wide. Ventral bar 30–31 (n 52) long; dorsal bar 22 (21–24; n 53) long. Germarium 208 (167–249; n 52) long, 115 (106–124; n 52) wide; testis 179 (118–240; n 52) long, 144 (112–176; n 52) wide.

Source of current specimens. Siganus riυulatus: Nabq Bay , Ras Mohammed National Park (South Sinai, Red Sea), Egypt (28 ° 029520N, 34 ° 269210E), 8 May 2003, 20 October 2005 .

Type host and locality. Siganus riυulatus: Gulf of Suez near Ras abu-Rudeis, Red Sea.

Site of infestation. Gills.

Specimens studied. Six voucher specimens, USNPC 99368, 99369, BMNH 2007.1.3.43, MPM 18854, MSNM Pi 3906, 3907.

Preυious records. Siganus riυulatus: Gulf of Suez near Ras abu-Rudeis, Red Sea as Pseudohaliotrematoides polymorphus suezicus by Paperna (1972b); Gulf of Gabès, Tunisia as Pseudohaliotrematodides polymorphus suezicus by Ktari and Ktari (1974); 8 km S of Eilat, Israel as Pseudohaliotrematoides polymorphus suezicus by Diamant and Paperna (1986); Mediterranean coast of Israel as P. p. suezicus by Diamant and Paperna (1986); various localities in the Mediterranean Sea as P. suezicus Paperna, 1972 by Diamant (1989); northern Gulf of Eilat, Israel as P. p. suezicus by Diamant et al. (1999).

Remarks. This species was originally described as a subspecies of Pseudohaliotrematoides polymorphus by Paperna (1972b). The subspecies was elevated to full specific rank by Diamant (1989), but Diamant et al. (1999) reversed this taxonomic revision without comment when the authors referred to the species as P. polymorphus suezicus . The species is now re-elevated to specific rank and transferred to Tetrancistrum based on the morphology of its haptoral armament and internal organ systems.

Figures

Figures 28–34. Tetrancistrum suezicum (Paperna, 1972) comb. n. from the marbled spinefoot, Siganus riυulatus, Ras Mohammed National Park, Egypt. (28) Whole mount (composite, ventral view). (29) Copulatory complex (dorsal view). (30) Ventral bar. (31) Dorsal bar. (32) Dorsal anchor. (33) FH loop of hook. (34) Ventral anchor. Scale bar: 400 Mm (28); 30 Mm (29–34).