Cercarioides cochleariformis (Rudolphi, 1819)

Dronen, Norman O., Blend, Charles K., Gardner, Scott L. & Jiménez, F. Agustín, 2007, Stictodora cablei n. sp. (Digenea: Heterophyidae) from the royal tern, Sterna maxima (Laridae: Sterninae) from Puerto Rico and the Brazos County area of the Texas Gulf coast, U. S. A., with a list of other endohelminths recovered in Texas, Zootaxa 1432 (1), pp. 35-56 : 50

Cercarioides cochleariformis (Rudolphi, 1819) ( Fig. 10 ).

Localities: Bryan Utility Lake , Bryan, Brazos County, Texas, U.S.A., 30° 24’ N latitude, 96° 13’ W longitude; Galveston Bay , Galveston County, Texas, U.S.A., 29 Ο 18' N latitude, 94 Ο 48' W longitude .

Site of infection: Intestine.

Deposited specimens: Voucher specimens (4 specimens) HWML 48501 .

Prevalence: 3 of 4 birds, 75%.

Intensity: 3 individuals/infected bird.

Basic comparative description: Based on 6 adult specimens. Body small, spinose, 3,950 (3,700 –4,150) by 800 (745–860) greatest width of hindbody; forebody expanded laterally forming wing-like expansions, 1,250 (1,100 –1,420) by 1,150 (1,050 –1,275). Mouth subterminal; oral sucker 215 (195–230) by 225 (200– 250); prepharynx short, 55 (40–95) long; pharynx longer than wide, 170 (130–210) by 130 (110–155); esophagus shorter than prepharynx, 25 (15–38); ceca long, terminating near posterior extremity. Acetabulum 190 (155–220) by 160 (125–190), with numerous fine spines on ventral surface. Gonotyl immediately sinistral to acetabulum. Testes smooth, tandem; anterior testis 250 (210–285) by 320 (290–365); posterior testis 270 (245–300) by 410 (390–440). Seminal vesicle bipartite, with anterior division thick-walled and posterior division thin- walled, posterior extent not visible. Genital pore immediately preacetabular, near midline of body. Ovary smooth, subspherical, situated immediately anterior to anterior testis, dextral to midline of body, 200 (185–225) by 240 (220–275). Vitelline follicles distributed along ceca from level of division of seminal vesicle to near end of ceca. Uterus distributed from level of acetabulogenital complex to posterior end. Eggs operculate, 30 (26–32) by 15 (12–16). Excretory pore terminal.

Remarks. Cercarioides cochleariformis has previously been reported from Sterna sp. from Brazil ( Yamaguti, 1971), but it represents a new host record for the royal tern in Texas, U.S.A. Yamaguti (1971) divided Cercarioides into 2 subgenera: Cercarioides (Witenberg, 1929) where the seminal vesicle is thinwalled and has 3 distinct divisions, and the vitellaria commence at the level of the anterior testis; and Allocercarioides Yamaguti, 1971 where the seminal vesicle is divided into 2 parts where the distal portion is thickwalled, and the vitellaria commence at or anterior to the level of the ovary. Our specimens have the characteristics of Allocercarioides , but unlike identified specimens of C. cochleariformis we examined, the forebody of our specimens was more laterally expanded than is typical of this species, forming almost wing-like expansions. Pearson (1973) listed Cercarioides cochlariformes as a synonym of Galactosomum cochleariformum .

Figures

FIGURE 10. Cercarioides cochleariformes, ventral view of adult. A, acetabulum; O, ovary; T, testis; U, uterus; W, lateral wing-like expansions of forebody. Scale bar: 10, 580µm.