Epitomapta aumakua, Solís-Marín & Conejeros-Vargas & Caballero-Ochoa & Byers, 2023

Solis-Marin, Francisco Alonso, Conejeros-Vargas, Carlos Andres, Caballero-Ochoa, Andrea Alejandra & Byers, Sheila Colleen, 2023, Epitomapta aumakua sp. nov., a new species of apodous sea cucumber from Hawai'i (Echinodermata, Holothuroidea, Apodida), ZooKeys 1183, pp. 73-80 : 73

Epitomapta aumakua sp. nov.

Figs 1 , 2 , 3

Type materials.

Holotype. MI 4942, 18.4 mm total length (TL), off Kualoa, O`ahu, Hawai`i, Pacific Ocean 21°30'N, 157°50'W, 2.5 m depth, July 1975. Paratypes. MI 4944, 2 specimens, 1 extensively dissected, same data as the holotype.

Type locality.

Off Kualoa, O`ahu, Hawai`i, Pacific Ocean 21°30'N, 157°50'W.

Diagnosis.

Body wall smooth, covered with small, oval-circular bumps, especially on anterior part of body. Tentacles 12, each with three pairs of lateral digits and a terminal digit; 6-8 sensory cups on each tentacle. Polian vesicle, 1/10 of body length; stone canal single, unbranched. Anchor and anchor plates of one kind: anchors usually exceeding 170 µm in length, plates exceeding 110 µm in length. Miliary granules scarce, only present in longitudinal muscles, relatively coarse, usually in form of simple flat, often faintly undulating, stout, straight rods with enlarged ends, slightly bent but never C-shaped, usually exceeding 20 µm in length. Tentacle ossicles shaped like smooth, flattened rods, not exceeding 50 µm in length, curved, with perforated ends; some rods broad (ca 14 µm in width) with few circular peripheral holes.

Holotype description.

18.4 mm long. Specimen uniformly whitish, body wall translucent when expanded. Anchors (Fig. 1A ) not projecting through body wall. Tentacles 12, each with three pairs of digits and a terminal digit; digits increase in length distally, and terminal digit longest. Inner (oral) surfaces of tentacles with double row of well-developed sensory cups; up to eight sensory cups on each tentacle. Ciliated funnels of various shapes (Fig. 2 ) occur on body wall, not on mesenteries. Two longitudinal rows of round-lipped, ciliated funnels present, each row attached to one side of one longitudinal muscle; a single V-shaped notch splits round lips of funnels and extends about 1/2 length of funnel. Polian vesicle single. Stone canal single, unbranched. Calcareous ring simple, stout, well developed (Fig. 3 ); radial pieces notched anteriorly, more conspicuous than that in interradial pieces; not pierced.

Ossicles. Body-wall deposits comprise anchors and anchor plates (Fig. 1A, B ). Anchors and plates at anterior, middle, and posterior body wall essentially similar. Anchors average 170 µm in length and 55 µm in largest width (width of the arms). Arms carry up to five conspicuous teeth; vertex smooth. Stock unbranched, but equipped with numerous small, sharp projections (Fig. 1A ). Anchor plates elongate, approximately oval, with numerous toothed perforations. Anchor plates average 110 µm in length and 90 µm in greatest width (Fig. 1B ). Miliary granules scarce, present only in epithelium covering longitudinal muscles, variable in shape but generally flat and tending to have enlarged endings. Granules up to ca 20 µm in length (Fig. 1D ). Tentacle ossicles small (40-50 µm in length), smooth, shaped like flattened, curved rods, with perforated ends (Fig. 1C ). Some rods flat and broad (ca 14-16 µm in width) having 6-10 circular peripheral holes.

Paratype variations. Specimens range from 16-17 mm in length.

Etymology.

The specific epithet aumakua refers, in Hawaiian mythology, to a person or family god that originated as a deified ancestor, who takes on physical forms as spirit vehicles. Here it is used as a non-Latin noun in apposition.

Ecology.

Epitomapta aumakua sp. nov. occurs at 2.5 m depth, buried in coarse sand.

Geographical distribution.

Known only from its type locality.

Figures

Figure 1. Epitomapta aumakua sp. nov. Holotype MI 4942 A anchors from mid-body, showing the detail of the posterior part B anchor plates from mid-body C rods from tentacles D miliary granules from the body wall.

Figure 2. Epitomapta aumakua sp. nov. Paratype MI 4944. Ciliated funnels showing their differing sizes and shapes.

Figure 3. Epitomapta aumakua sp. nov. Holotype MI 4942, calcareous ring. Abbreviations: r = radial piece, ir = interadial piece.