Menziesia sebastodis ( Yamaguti, 1934 ) Whittington & Deveney & Wyborn, 2001

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 : 755-757

Menziesia sebastodis ( Yamaguti, 1934) comb. nov.

(®gures 40, 41)

Synonyms. Epibdella sebastodis Yamaguti, 1934 ; Benedenia sebastodis ( Yamaguti, 1934) Meserve, 1938 .

Material studied. MPM: No. 22772 (holotype and paratype) (1 slide, 2 individuals) ex gills of Sebastodes (now Sebastes , see Eschmeyer, 1990) inermis (Cuvier in Cuvier and Valenciennes) ( Scorpaenidae ) from Ise Bay, Japan.

Observations. This species was reasonably well-described by Yamaguti (1934) who based his account on two specimens. Unfortunately some anatomical details of the holotype are obscured by dark staining. Iwata (1990) redescribed the species in reasonable detail, but deposited no specimens. We oOEer the following summary of M. sebastodis including information not included in previous descriptions. Menziesia sebastodis is less than 2 mm long and is, therefore, a small species (e.g. ®gure 3C). The anterior attachment organs, which are a little larger than the pharynx, appear to be bipartite (e.g. ®gure 1C) and hooded. Gland cells are present between the pharynx and the anterior attachment organs (®gure 41). Yamaguti described the haptor as`bell-shaped’ but this appearance is due to folding of the haptor of the holotype. The haptor of the paratype has the more characteristic shape shown in ®gure 40A. The accessory sclerites are centrally placed, relatively small (74 ±82) 78, and tendons pass through the notch at their proximal ends (®gure 40A). The anterior and posterior hamuli are slender, of similar size, have an irregular shape and the anterior pair overlap the posterior pair by one-third to one-half of their length (®gure 40A). The small lobes of the marginal valve are arranged as follows: four lobes between hooklets of pair II; six lobes between hooklets II and III; four lobes between hooklets III and IV; three lobes between hooklets IV and V; four lobes between hooklets V and VI; six lobes between hooklets VI and VII; 10 lobes between hooklets VII and VIII; 10 lobes between hooklets of pair VIII.

Yamaguti (1934) neglected to mention glands of Goto, but we observed three structures posterior to the testes in the paratype that may be glands of Goto. The testes are perforated by columnar structures. The accessory gland reservoir lies dorsal to the proximal end of the thin penis which is less sigmoid than those of other Menziesia species. The vagina is conspicuous, appears wide and muscular along most of its length and opens submarginally near, but posterior to, the common genital pore. The vagina of both specimens appears to be sperm-®lled and the paratype possibly contains a spermatophore. We believe that the`oval compact organ of unknown nature’ described by Yamaguti (1934) is probably a vaginal seminal receptacle (®gure 41). Both specimens have a lobe dorsal, and mostly anterior, to the common genital pore (®gure 41).

Type-host and locality. Sebastodes (now Sebastes ) inermis ( Scorpaenidae ), Ise Bay, Japan.

Published records and descriptions. Yamaguti (1934); Iwata (1990).

Published host record. Scorpaenidae : Sebastodes (now Sebastes ) inermis.

Site . Gills.

Distribution. Ise Bay, Japan ( Yamaguti, 1934); Coast of Hukuoka Prefecture, Japan ( Iwata, 1990).

Remarks. Bychowsky (1957) suggested that, like Benedenia (now Megalobenedenia ) derzhavini (see Egorova, 1994) and B. ovata , M. (as Benedenia ) sebastodis possessed muscular septa on the ventral surface of the haptor. Our examination of type material of M. sebastodis revealed no sign of septa, but we observed some folds on the haptor that may be mistaken for septa. We conclude that this species displays features of Menziesia , such as a long penis with an accessory gland reservoir dorsal to its proximal end and a capacious vagina with muscular walls. It is unfortunate that only two specimens are available for study because not all of the anatomy could be observed clearly. The lack of adequate specimens of this species highlights the need for voucher specimens of previously described species to be deposited in museums, where possible; Iwata did not deposit any specimens of M. sebastodis . Further study of fresh material should enable a more accurate analysis and clarify its position in Menziesia .

Menziesia sebastodis is most similar to M. malaboni . Menziesia malaboni and M. sebastodis each have slender anterior and posterior hamuli (®gures 36B, D, E and 40A, C, D, respectively), but the posterior hamuli of M. sebastodis are twice the length and are more ®lamentous than those of M. malaboni . Although the anterior hamuli of these species are of similar length, M. malaboni exceeds the size of M. sebastodis in all other parameters. Both species appear to have a conspicuous vaginal seminal receptacle. In M. sebastodis , the entire accessory gland reservoir lies dorsal to the proximal end of the penis (®gure 41). In M. malaboni , however, the accessory gland reservoir overlaps the proximal end of the penis for approximately one-third of the length of the reservoir (®gure 36A). The vagina of M. sebastodis is also more muscular than that of M. malaboni .