Atys multistriatus Schepman, 1913

Too, Chin Chin, Carlson, Clay, Hoff, Patty Jo & Malaquias, Manuel António E., 2014, Diversity and systematics of Haminoeidae gastropods (Heterobranchia: Cephalaspidea) in the tropical West Pacific Ocean: new data on the genera Aliculastrum, Atys, Diniatys and Liloa, Zootaxa 3794 (3), pp. 355-392 : 368-370

Atys multistriatus Schepman, 1913

Atys multistriata Schepman, 1913: 468 , pl. 32, fig. 2.

Atys multistriatus — Carlson & Hoff 2000: 170. Gosliner et al. 2008: 23.

Type locality. Balabalagan Islands, between Borneo and Sulawesi ( Paternoster Islands )

Material examined. Mariana Islands, Guam, 2 spcs dissected, UF 374136, H = 6.27 mm, 6.6 mm.

Animal ( Fig. 1D ): Body whitish-translucent, white dots scattered all over body, red dots and white blotches on mantle; eyes visible.

Shell ( Figs 2E , 9A, B ): Maximum height 11.75 mm; whitish; fragile, thin, semi-translucent, elongated, oval, with slightly convex sides, anterior end protruded, posterior end truncated; spire sunken, outer lip elevated slightly above the apex, aperture narrow posteriorly and broader anteriorly, columella short, slightly concave, with a fold at the base; spiral grooves throughout shell but weaken in middle part, conspicuous axial lines present, creating netlike pattern all over the shell but weaken in middle part.

Jaws: Elongated with multiple denticles ( Carlson & Hoff 2000).

Radula: Radular formula at mid-point 21–23 x 5–4.1.4–5; median tooth broad, slightly bilobed, with weak denticulation and small lateral cusp; outer lateral teeth hook-shaped, with weak denticulation ( Carlson & Hoff 2000). There is no differentiation between inner and outer lateral teeth.

Gizzard plates ( Figs 9C–E ): Three gizzard plates; broader at anterior part, narrower towards posterior end; 20 ridges, thick, become crescent-shaped towards both ends, middle ridges inverted V-shaped, ridges covered by single rows of tiny rods with pointed tips along top edge, both anterior and posterior sides of ridges smooth.

Male reproductive system ( Fig. 9F ): Total length 3 mm (H = 6.27 mm). Formed by three parts: prostate, seminal duct and penial region; prostate single-lobed, ovoid, translucent; long seminal duct connects the prostate to penial region, about four times the length of prostate, opaque-yellow; penial region cylindrical-elongated, about half of the length of seminal duct, slightly broader than seminal duct, semi-translucent.

Ecology. Shallow water, reef flat to 21 m depth on sandy bottom ( Carlson & Hoff 2000; Gosliner et al. 2008).

Geographical distribution. Indonesia, the Philippines, Guam, Palau, Hawaii, Tahiti, Fiji ( Kay 1979; Carlson & Hoff 2000; present study).

Remarks. This species has a conspicuous reticulated sculpture on the shell, which is uncommon among haminoeids species. This feature can also be seen in Schepman’s (1913: pl. 32, fig. 2a, b) illustration of the holotype. Jaws and radula could not be successful prepared for SEM and descriptions are based on Carlson & Hoff (2000). According to the latter authors, this species possesses a bilobed median tooth with fine denticulation. This feature is known in the Mediterranean and eastern Atlantic species Atys macandrewii ( Martinez & Ortea, 1998) and was found in the new species here described and named Atys pittmani . The shell of Atys multistriatus and its anatomy differs from the type species Atys naucum . The disparity of shell shapes and anatomies across Atys species hints that the genus may not be monophyletic. Preliminary molecular phylogenetic results ( Too 2011) point in this direction, but a generic splitting of Atys will require the use of a broader taxon sampling; therefore, we refrain to do it at this stage.

Figures

FIGURE 1. Live images. A. Aliculastrum cylindricum (Koumac, northern New Caledonia; H = 28 mm, MNHN, Paris), B. Aliculastrum debilis (Maui, Hawaii; ZMBN 81658; H = 9 mm), C. Aliculastrum parallelum (Guam; UF 374138; H = 19 mm), D. Atys multistriatus (Guam; UF 374136; H = 7 mm), E. Atys pittmani nov. sp. (Maui, Hawaii; ZMBN 81673; H = 10 mm), F. Atys semistriatus (Maui, Hawaii; ZMBN 81656; H = 6 mm), G. Atys ukulele nov. sp. (Maui, Hawaii; ZMBN 89710; H = 5.4 mm), H. Diniatys dentifer (Guam; UF 374130; H = 9 mm), I. Diniatys dubia (Guam; UF 299907; H = 12.7 mm), J. Liloa curta (Guam; UF 374131; H = 15 mm), K. Liloa porcellana (Maui, Hawaii; ZMBN 89712; H = 4.2 mm); L. Liloa porcellana (Maui, Hawaii; ZMBN 89712; H = 2.8 mm). Image A, courtesy of W. B. Rudman; Images B, E–G, K, L, courtesy of C. Pittman.

FIGURE 2. Shells. A. Aliculastrum cylindricum (the Philippines; MNHN, Paris (S3/ OT236); H = 22 mm), B. Aliculastrum cylindricum (New Caledonia; MNHN, Paris; H = 13.7 mm), C. Aliculastrum debilis (the Philippines; MNHN, Paris (OT834); H = 4.5 mm), D. Aliculastrum parallelum (Guam; UF 374138; H = 10 mm), E. Atys multistriatus (Guam; UF 374136; H = 5.3 mm), F. Atys pittmani nov. sp. (Maui, Hawaii; ZMBN 81673; H = 10 mm); G. Atys semistriatus (Tahiti; ZMBN 87082; H = 4.1 mm). Scale bar: 1 mm.

FIGURE 9. Shell and anatomy of Atys multistriatus. A. Detail of anterior part of shell. B. Detail of posterior part of shell. C. Top view of gizzard plate. D. Middle ridges on gizzard plate. E. Rods on middle ridges of gizzard plate. F. Male reproductive system. go, genital opening; pr, prostate; ps, penial sheath; sd, seminal duct. Scale bars: A, C = 100 µm; B = 200 µm; D = 10 µm; E = 2 µm; F = 1 mm. A, C–F: UF 374136, H = 6.27 mm; B: UF 374136, H = 6.6 mm.