Heterochaerus sargassi ( Hyman, 1939 )

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 : 14-15

Heterochaerus sargassi ( Hyman, 1939)

( Fig. 6 B)

Amphiscolops sargassi: Hyman 1939 ; Marcus 1947 (p 161); Marcus 1949 (p 9); Marcus 1950 (p 44); Marcus 1952 (p 18); Marcus 1954 (p 15); Dörjes 1968 (p 87); Dörjes 1970 (p 262); Dörjes and Young 1973 (p 350); Dörjes and Karling 1975 (p 177).

Heterochaerus sargassi: Winsor 1990 (p 798).

Material. Living immature specimens in squeeze preparation.

Locality. The beach of the CEBIMar laboratory, Praia do Segredo, São Sebastião, São Paulo, Brazil, subtidally from Sargassum sp. (23°49’39.1”S, 45°25’20.5”W).

Description. Immature specimens ~ 1.4 mm in length and ~ 140 m wide ( Fig. 6 B). With many gold-colored zooxanthellae endosymbionts. Statocyst absent. Red eyespots visible at anterior end of smallest specimens.

Remarks. Although the specimens of Heterochaerus sargassi originally described by Hyman (1939) lacked sexual organs, Marcus (1950) collected sexually mature specimens from Ilhabela. Except for their lack of reproductive organs, our specimens match Marcus’s (1950) description.

Figures

FIGURE 6. Photomicrographs of living specimens. A. Amphiscolops evelinae. B. Heterochaerus sargassi.