Benedenia scari Yamaguti, 1968

Whittington, I. D., Deveney, M. R. & Wyborn, S. J., 2001, A revision of Benedenia Diesing, 1858 including a redescription of B. sciaenae (van Beneden, 1856) Odhner, 1905 and recognition of Menziesia Gibson, 1976 (Monogenea: Capsalidae), Journal of Natural History 35 (5), pp. 663-777 : 725-726

Benedenia scari Yamaguti, 1968

(®gures 16E, 19M±O)

Material studied. USNPC: No. 63589 (holotype) (1 slide, 1 specimen) ex gills of Scarus sordidus (5 Chlorurus sordidus , see Bellwood, 1991) ( Scaridae ) from Hawaii; MPM: No.15405 (paratypes) (1 slide, 3 specimens) ex gills of S. sordidus (5 Chlorurus sordidus ) ( Scaridae ) from Hawaii.

Observations. This reappraisal of B. scari , one of four species described by Yamaguti (1968) from Hawaiian ®shes, is based on the same whole-mounts that he studied. Yamaguti (1968) mentioned that this species was described from ®ve specimens, but we traced only the holotype and three paratypes. Benedenia scari was mostly well-described by Yamaguti but some supplementary information is provided below, although the types are generally of poor quality.

Some of the haptoral sclerites in the four specimens studied appear to be of diOEerent shapes but this seems to be due to their orientation in the material. The accessory sclerites of B. scari are relatively small (table 2; ®gures 16E, 19M) and the anterior hamuli have a distinct recurved distal tip and a broad root (®gure 19N). The proximal ends of the anterior hamuli overlap the proximal tips of the accessory sclerites and the distal portions of the anterior hamuli overlap the proximal ends of the posterior hamuli for half to two-thirds of their length (®gure 16E). All median sclerites are displaced posteriorly on the haptor (®gure 16E). Yamaguti observed only 12 hooklets but we counted 14. The path of the tendons (®gure 16E) was di cult to observe and was seen in only a single specimen. The accessory sclerites are small and may have a reduced function in attachment. The marginal valve is wide, indented strongly at each hooklet with small single lobes between hooklets on the posterior edge of the haptor and larger lobes comprising smaller fused lobes between hooklets at the anterior edge of the haptor (®gure 16E). The haptor of B. scari has conspicuous submarginal muscle ®bres (®gure 16E).

Yamaguti (1968) described the`prostatic reservoir’ (5 accessory gland reservoir) as being outside the`cirrus pouch’ (5 penis canal) and depicted this feature in his ®gure 4A and C in a way which does not represent accurately the structure of these organs (®gure 2B). The accessory gland reservoir of B. scari is large, weakly muscular and lies proximal to the slender, muscular penis canal and is enclosed by a proximal extension of the wall of the penis canal. Yamaguti (1968) gave a lengthy description of the glands of Goto and their connection to the vas deferens and reported the presence of coloured granules in the connecting ducts but these details were not visible in specimens we studied. The vagina of B. scari is narrow along its entire length including the proximal vaginal seminal receptacle.

Type-host and locality. Scarus sordidus (5 Chlorurus sordidus ) ( Scaridae ), Hawaii.

Published record and description. Yamaguti (1968).

Published host records. Scaridae : Scarus sordidus (5 Chlorurus sordidus ).

Site . Gills.

Distribution. Hawaii.

Remarks. Benedenia scari was not compared with any other species by Yamaguti (1968) and was characterized only by its small accessory sclerites. Yamaguti did distinguish B. scari from its Hawaiian relatives in his unworkable key by the poorly developed vaginal seminal receptacle, vitelline reservoir and`cirrus’. Benedenia scari can be better separated from its Hawaiian counterparts, and from all species of Benedenia , by a combination of the following features: the posterior location of the median haptoral sclerites (®gure 16E); the shapes of the accessory sclerites and the anterior hamuli (®gure 19M, N); the small size of the accessory sclerites; the presence of wavy musculature around the perimeter of the haptor (®gure 16E).