Bispira melanostigma (Schmarda, 1861)
Figure 1 B
Sabella melanostigma Schmarda, 1861 (36, pl. 22, Fig. 190); Uebelacker, 1984 (54-42, 54-43, Gulf of Mexico, part); Sabella variegata Kroyer, 1856; Sabella thoracica Kroyer, 1856; Sabella bipunctata Baird, 1865; Bispira melanostigma Knight-Jones and Perkins, 1998 (415–419, Figs 11, 12).
Material examined. Several specimens occurring as epiphytes on Thalassia leaves collected at 0.5 m in the main channel of the Twin Cays (sample CBC-TC Chan, others from a meadow off the N-E external side of Twin Cays entrance (sample CBC-KF 1019).
Remarks. This species, commonly reported in the Caribbean area (Tovar-Hernández and Salazar-Vallejo, 2006) is similar in size to B. brunnea, apart from the smaller length of its crown. This species is characterized by asexual reproduction as seen in B. brunnea (Knight-Jones and Perkins, 1998) and can be found in aggregations of individuals. The shape of the companion chaetae of the thorax is unusual for the genus in that they are not geniculate (Fig. 1 B). The distribution seems to be centered in the Caribbean and in the Gulf of Mexico, extending northward as far as North Carolina and Bermuda. Good descriptions and figures are available in Knight-Jones and Perkins (1998) and Tovar-Hernández and Salazar-Vallejo (2006).