Kuma asilhas, Hooge, Matthew D. & Rocha, Carlos E. F., 2006

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 : 19-21

Kuma asilhas sp. nov.

( Figs. 11–12 )

Type material. Holotype. MZUSP PL. 186, one set of 2-µm-thick serial sagittal sections of epoxy-embedded male-immature specimen stained with toluidine blue. Paratype. MZUSP PL. 187, epoxy-embedded whole mount.

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

Other material examined. Living specimens in squeeze preparations; one set of 2- µm-thick serial sections of male-immature epoxy-embedded specimen; whole mount for fluorescence imaging of musculature.

Etymology. Species name comes from the type locality, As Ilhas.

Description. Mature specimens ~600 µm long to ~ 1.2 mm long when fully elongated and ~100 µm wide ( Figs. 11 A, B). Body cylindrical. Anterior and posterior ends rounded; posterior more blunt. Body color yellow by transmitted light. Epidermis completely ciliated. Without conspicuous rhabdoid glands. Frontal organ well developed. Mouth opening on ventral surface, middle of body ( Fig. 12 A).

Body-wall musculature with circular muscles that encircle the body along entire length of animal; straight longitudinal muscles present between frontal pore and anterior edge of mouth; longitudinal-cross-over muscles (fibers with a longitudinal orientation anteriorly, but bend medially to cross diagonally) present in both dorsal and ventral body wall; longitudinal muscles in anterior half of body that wrap around posterior rim of mouth (U-shaped muscles) present in ventral body wall; anterior end with ventral diagonal muscles positioned between outer circular and inner longitudinal muscles ( Fig. 12 A).

Ovary unpaired, ventral. Testes paired, lateral to ovary, compact; separate from ovary ( Fig. 11 C).

Female gonopore, seminal bursa, and female accessories all absent.

Male gonopore terminal at posterior end of body ( Figs. 11 C, 12B). Proximal opening of ciliated male antrum surrounded by ring of large mucoid glands whose tips open into antrum ( Fig. 11 C). Antrum musculature composed of circular and longitudinal muscles ( Fig. 12 B). Large cluster of sperm that branches bilaterally toward testes positioned at proximal end of mucoid glands ( Figs. 11 C).

Remarks. Of the presently known species within the genus Kuma , K. asilhas is most similar to K. flava Hooge and Smith, 2004. However, K. asilhas has a longer body, a less intense yellow coloration and is without the conspicuous rhabdoid glands found in K. flava .

Figures

FIGURE 11. Kuma asilhas sp. nov.; photomicrographs of living specimen. A. Dorsal view of elongated and squeezed living specimen. B. Dorsal view of squeezed living specimen. C. Dorsal view of male copulatory organ.

FIGURE 12. Kuma asilhas sp. nov.; whole-mount stained with Alexa- 488 - labeled phalloidin and viewed with confocal microscopy. A. Projection of anterior ventral body-wall musculature. B. Projection of male antrum musculature.