Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Life history, pathology, and description of Kudoa ovivora n. sp. (Myxozoa, Myxosporea): an ovarian parasite of Caribbean labroid fishes.

Abstract

Kudoa ovivora sp. nov. is described and figured from the ovaries of bluehead wrasse, Thalassoma bifasciatum, and reported from Halichoeres bivittatus, H. garnoti, H. poeyi, Sparisoma aurofrenatum, S. radians and S. rubripinne, collected in the San Blas Islands on the Caribbean side of Panama in 1993 and 1996. K. ovivora spores differ from those of most other Kudoa species; they are quadrate with rounded edges in apical view, and oval-shaped with apical valve extensions in side view (mean spore dimensions: length 6.5 µm, width 7.7 µm, thickness 6.9 µm; mean polar capsule dimensions: length 2.1 µm, width 1.5 µm). This is the first Kudoa species reported from gonads of fishes. The prevalence of infection varied from 4.7% (5 of 106) in H. bivittatus to 40.1% (416 of 1038) in the 1996 sample of T. bifasciatum (the only S. rubripinne examined was also infected). The density of infection, measured as the percentage of eggs infected, also varied among species, with the highest densities (commonly over 95%) in H. garnoti. Fishes fed infected tissue developed more infections than unfed fish (P<0.0025), suggesting that K. ovivora may not require an intermediate host. Infected eggs were unviable, and larger and heavier than uninfected eggs; they contained more organic and inorganic material, indicating that K. ovivora increases resource allocation to eggs. Therefore, infected females may have reduced growth, fecundity, and/or spawning activity. Because males were uninfected and all identified hosts are protogynous sequential hermaphrodites, further studies of K. ovivora may provide new insights into the costs and benefits of sex change. An appendix summarises the taxonomic characteristics of all known Kudoa species.