Paratomella rubra Rieger and Ott, 1971

Hooge, Matthew D. & Rocha, Carlos E. F., 2006, Acoela (Acoelomorpha) from the northern beaches of the state of São Paulo, Brazil, and a systematic revision of the family Otocelididae, Zootaxa 1335, pp. 1-50 : 45-46

Paratomella rubra Rieger and Ott, 1971

( Figs. 30 )

Material. Living specimens in squeeze preparation; whole mounts for fluorescence imaging of musculature.

Locality. As Ilhas, São Sebastião, São Paulo, Brazil, from subtidal fine-grained sand (23°47’16.0”S, 45°42’31.2”W).

Description. Living specimens ~ 1.5 mm long and 70 m wide ( Fig. 30 A). Elongate, filiform body with blunt posterior end. Posterior end with adhesive haptocilia. Body color bright red in transmitted light ( Figs. 30 A–C). Mouth opening on ventral surface, anterior half of body. Sexual forms with testes and male copulatory organ positioned anterior to ovaries and eggs. Male gonopore opens to a large ciliated antrum that leads to a muscular, sperm-filled seminal vesicle and associated penis needles ( Fig. 30 C).

Remarks. Paratomella rubra is a cosmopolitan species. Although all the specimens we collected were sexual forms, the species can also be found in asexual paratomizing chains of two ( Creze 1978).

Figures

FIGURE 30. Paratomella rubra; photomicrographs of living specimen. A. Dorsal view squeezed specimen. B. Dorsal view of anterior. C. Copulatory organs.