Ascocotyle (Leighia) chandleri Lumsden, 1963

Scholz, T., Aguirre-Macedo, M. L. & Salgado-Maldonado, G., 2001, Trematodes of the family Heterophyidae (Digenea) in Mexico: a review of species and new host and geographical records, Journal of Natural History 35 (12), pp. 1733-1772 : 1740

Ascocotyle (Leighia) chandleri Lumsden, 1963

(®gure 1F)

Metacercaria

Morphology. Metacercaria of this species found in Mexico was described by Scholz et al. (1997a: 166; ®gure 2F±H). The authors identi®ed this metacercaria as A. (L.) chandleri on the basis of the presence of 281 29 circumoral spines, a large, branched excretory bladder, the morphology of the terminal genitalia with a large, pad-like gonotyl with several refractile bodies, the anterior position of the testes and the site of infection in the second intermediate host belonging to the same family as the type host, Cyprinodon variegatus .

Second intermediate host. Fundulus persimilis (Cyprinodontidae) .

Site of infection. Intestinal wall.

Distribution. YucataÂn (CheleÂm lagoon).

References from Mexico. Scholz et al. (1997a).

Specimens deposited. IPCAS D-352.

Comments. Only one metacercaria was found during a study on the species of Ascocotyle parasitizing ®sh in southeastern Mexico ( Scholz et al., 1997a). Since it was partially damaged and studied within the cyst, new material is necessary to con®rm the occurrence of A. (L.) chandleri in Mexico. Ascocotyle (L.) chandleri was described from metacercariae encysted in the liver of Cyprinodon variegatus (Cyprinodontidae) and Mollienesia latipinna (5 Poecilia latipinna (Lesueur)) from Texas, USA ( Lumsden, 1963). This author also found an immature worm, supposedly conspeci®c with A. (L.) chandleri , in the great egret ( Casmerodius albus ).

Lumsden (1963) reported 54 circumoral spines in A. (L.) chandleri forming two circlets of 27 spines each but examination of a paratype from Cyprinodon variegatus (USNPC 54894) revealed the presence of only 46 (231 23) spines (®gure 1F), indicating variation in the number of spines in this species.

Adults of this trematode were ®rst found in the roseate spoonbill ( Ajaia ajaja (5 Platalea ajaja Linnaeus )) from Texas ( Dronen, 1985). SepuÂlveda et al. (1996) reported A. (L.) chandleri from the little blue heron ( Egretta caerulea (Linnaeus)) from Florida, with high values of prevalence (45%) and mean intensity of infection (385 specimens; range 1±3986).

Although Yamagut i (1971) placed this species within the nominotypical subgenus Ascocotyle , its morphology (vitelline follicles between the ventral sucker and testes, the uterus reaching anteriorly to the pharynx, long intestinal caeca reaching to the testes) corresponds to the diagnosis of the subgenus Leighia as proposed by Sogandares-Bernal and Lumsden (1963). Therefore, this species is considered here to be a member of the subgenus Leighia .