Baltalimania salinsula, Atherton & Jondelius, 2022

Atherton, Sarah & Jondelius, Ulf, 2022, Diversity in the family Isodiametridae (Acoela): New species bring back old problems, Zootaxa 5169 (5), pp. 401-424 : 408-409

Baltalimania salinsula sp. nov.

Figure 4

Zoobank registration. urn:lsid:zoobank.org:act:7464785C-58B6-499C-BDCA-BEF48B373812

Materials examined. Digital video and photographs of original living specimen, Holotype ( SMNH Type-9425)

Type locality. Saltö Badstrand , Strömstad, Sweden ; 58°52’41 N, 11°06’56 E

Habitat. 2 m depth, marine, medium sand

Diagnosis. Body length 0.85 mm. Body pigmentation absent. Frontal organ small. Rhabdoid glands distributed in longitudinal rows. Vacuoles absent. Paired testes and ovaries. Seminal bursa absent. Male copulatory organ with penis partially invaginated into the seminal bursa. Penis 27 µm long, curved. Male gonopore subterminal.

Etymology. This species is named for its type locality, Saltö (Latin: sal salt; insula island)

Description. Living specimen 0.85 mm long and to 0.18 mm maximum width. Free-swimming specimens elongate with rounded anterior end and pointed posterior. Body colorless, except for parenchyma, which is dark yellow or brown from food. Numerous lipid droplets of varying sizes present in digestive parenchyma and throughout the body, clear to yellow in color. Digestive parenchyma extends from just posterior of statocyst to posterior eggs. Mouth not observed.

Frontal organ small, not extending to level of statocyst. Statocyst present 115 µm from anterior end, 15 µm in diameter with 11 µm statolith. Vacuoles absent.

Epidermis completely ciliated. Cilia 6–7 µm long. Rhabdoid glands distributed in longitudinal rows. Posterior rhabdoid glands partially subepidermal, colorless, 8–10 µm in length.

Ovaries and testes paired. Ovaries anterior to male copulatory organ, present in the posterior ~¼ of the animal. Seminal bursa absent. Vagina and female gonopore not observed.

Male copulatory organ close to posterior end, globular with a width of 56 µm and a length of 52 µm. Penis partially invaginated into seminal vesicle. Penis small, 27 µm long, and curved. Male gonopore located at ventral midline.

Figures

FIGURE 4. Baltalimania salinsula sp. nov. A. micropictograph of the posterior focusing on the reproductive structures B. drawing of the whole body C. micropictograph of the whole body D. micropictograph of the male copulatory organ; dp digestive parenchyma, eg egg, f frontal organ, l lipid globule, mco male copulatory organ, mp male gonopore, p penis, r rhabdoid glands, st statocyst, t testes, v vacuole.