Atys ukulele, Too & Carlson & Hoff & Malaquias, 2014

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 : 377

Atys ukulele nov. sp.

Type locality. Black Rock, Maui Island , Hawaii

Etymology. This species is only known from Hawaii and we named it after a traditional musical instrument of these islands, the ukulele guitar, a “derived form” of the Portuguese “cavaquinho” guitar introduced in Hawaii during the 19 th century by Portuguese immigrants.

Material examined. Maui, Hawaii, 1 spc. dissected, ZMBN 89710 , H = 5.4 mm. Black Rock, Maui , Hawaii, 1 spc. sequenced, ZMBN 89707 (holotype), H = 3.5 mm. Black Rock, Maui, Hawaii, 1 spc., ZMBN 89708 (paratype), H = 4.2 mm. Black Rock, Maui, Hawaii, 1 spc., ZMBN 89709 (paratype), H = 3.1 mm .

Animal ( Fig. 1G ): Body whitish-translucent, white dots scattered over the body, more dense on edges and mid part (between mouth and eyes) of cephalic shield, forming light yellowish blotches on the mantle, dark dots scattered over the parapodial lobes; eyes visible, inserted on unpigmented periocular areas.

Barcode: GenBank Accession No KF735658 ( ZMBN 89707).

Shell ( Figs 3A , 13A, B ): Maximum height 5.4 mm; whitish; fragile, semi-translucent, barrel-shape, elongated, widest right below the mid-line, anterior end protruded, posterior end truncated; spire sunken, outer lip elevated above the apex, aperture narrow posteriorly and slightly broader anteriorly, umbilicus present; step-like spiral grooves at both ends (anterior = 11, posterior = 11), which become closer towards the ends, faint bands at the middle part.

Jaws: Present, crescent shape.

Radula ( Figs 13D–G ): Radular formula at mid-point 23 x 6.1.6; median tooth bilobed with broad base, and conspicuous denticulation along edge, shorter triangular lateral cusps present; outer lateral teeth hook-shaped, broad base with semi-circular projection outwardly, groove along inner margin, weak denticulation along outer margin, size decreases outwardly. There is no differentiation between inner and outer lateral teeth.

Gizzard plates ( Figs 13H, I ): Three gizzard plates; long and narrow; 18 ridges on each side of pseudo-rachis, ridges covered by single rows of tiny rods with pointed tips along top edge of ridges, both anterior and posterior sides of ridges smooth.

Male reproductive system: Unknown.

Ecology. Sandy bottom between 6–17 m deep (present study).

Geographical distribution. Maui, Hawaii (present study).

Remarks. This species has a bulloid shell more elongated than Atys semistriatus . The colour patterns of Atys semistriatus and Atys ukulele nov. sp. are distinct. The former has large conspicuous red blotches in the mantle and dark spots scattered over the cephalic shield, whereas Atys ukulele has a mantle pigmented with faint, almost inconspicuous yellowish blotches and a cephalic shield with white dots along the edges and between the eyes. Moreover, Atys ukulele has a distinct radular median tooth, slightly bilobed with the presence of conspicuous denticulation along the margin. The reproductive system was damaged during dissection hindering comparison with Atys semistriatus .

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 3. Shells. A. Atys ukulele nov. sp. (Maui, Hawaii; ZMBN 89711; H = 4.6 mm), B. Diniatys dentifer (the Philippines, MNHN, Paris (B17/ OT793); H = 3.5 mm), C. Diniatys dubia (Guam; UF 299907; H = 7.5 mm), D. Liloa curta (the Philippines; MNHN, Paris (S12/ OT575); H = 3.1 mm), E. Liloa porcellana (Guam; UF 299895; H = 6.7 mm), F. Liloa porcellana (Maui, Hawaii; ZMBN 89712; H = 4.2 mm), G. Liloa porcellana (Maui, Hawaii; ZMBN 89712; H = 2.8 mm). Scale bar: 1 mm.

FIGURE 13. Shell and anatomy of Atys ukulele nov. sp.. A. Detail of anterior part of shell. B. Detail of middle part of shell. C. Detail of posterior part of shell. D. Anterior part of radula. E. Detail of median tooth at the anterior part of radula. F. Detail of outer lateral teeth at left side of radula. G. Weak denticulation along the outer margin of lateral teeth at the posterior of radula. H. Top view of gizzard plate. I. Rods on middle ridges of gizzard plate. Scale bars: A–C = 200 µm; D = 20 µm; E–G, I = 10 µm; H = 30 µm. A–I: ZMBN 89710.