Waminoa Winsor, 1990

Ogunlana, Maxina V., Hooge, Matthew D., Tekle, Yonas I., Benayahu, Yehuda, Barneah, Orit & Tyler, Seth, 2005, Waminoa brickneri n. sp. (Acoela: Acoelomorpha) associated with corals in the Red Sea, Zootaxa 1008 (1), pp. 1-11 : 9-10

Waminoa Winsor, 1990 (emend)

Diagnosis. Convolutidae discoid to obcordate in shape; color results from pigments and symbiotic algae; often with two coexisting species of algal symbionts; brain insunk; mouth ventral and in posterior third of body; rhabdoids present; ovaries and testes paired; with sub­terminal male genital pore. Male copulatory organ composed of muscular seminal vesicle filled with sperm. Female gonopore present or absent. Seminal bursa with 2 or more (2–8) bursal nozzles. Statocyst and eyes absent in mature forms, but present in immature specimens. Frontal organ absent. Epizoic on corals.

Type species. Waminoa litus Winsor, 1990

Remarks. Whether either of the two Waminoa species are synonymous with species of Haplodiscus remains a possibility. Most of these Haplodiscus species were described from only a paucity of specimens collected in plankton tows and, except for H. piger , not observed alive ( Dörjes 1970). Clarifying the relationship between Haplodiscus and Waminoa awaits finding more live material of both genera.

The two algal symbionts in Waminoa brickneri are species of Symbiodinium and an Amphidinium­ like dinoflagellate and reside intracellularly within parenchymal cells. Like other convolutids, W.brickneri probably does not rely solely on its symbionts for nutrition. It does not appear to consume coral tissue, however, in that no nematocysts occur in its digestive tissue.

Coral­infesting acoels like Waminoa brickneri are likely to be widespread, occurring wherever there are shallow tropical reefs. Besides the published reports of occurrence in the Coral Sea, the Red Sea, and Micronesia, anecdotal reports on reef­animal Web sites as well as some unpublished reports of it in waters off Kenya and Tanzania (Yehuda Benayahu personal comm.) and Indonesia (Gustav Paulay personal comm.) show distribution in the Indo­Pacific region. As Trench & Winsor (1987) suggested for Waminoa , its coral­infesting form may be a benthic phase in a life cycle involving also pelagic individuals, which would be identified as species of Haplodiscus . Occurrence of Haplodiscus species in the Bahamas, the Gulf Stream, the Sargasso, the North Equatorial Current, and the Gulf of Naples (see distribution records and literature in Tyler et al. 2005) hint at occurrence of coral­associated acoels in the Atlantic Ocean and Mediterranean Sea as well.