Diversity and systematics of Haminoeidae gastropods (Heterobranchia: Cephalaspidea) in the tropical West Pacific Ocean: new data on the genera Aliculastrum, Atys, Diniatys and Liloa Author Too, Chin Chin Author Carlson, Clay Affiliated to: Marine Laboratory, University of Guam, Mangilao, GU 96923 Author Hoff, Patty Jo Affiliated to: Marine Laboratory, University of Guam, Mangilao, GU 96923 Author Malaquias, Manuel António E. text Zootaxa 2014 2014-05-07 3794 3 355 392 journal article 5612 10.11646/zootaxa.3794.3.3 74c8a3cd-c737-41aa-b574-04ef00c173f7 1175-5326 4914927 A9A30A4F-D095-47EE-9120-B0B5A7BCCE88 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). TABLE 1. Summary of most useful characters for diagnosis of species of Aliculastrum .

A. cylindricum ( Helbling, 1779 )	A. debilis ( Pease, 1860 )	A. parallelum ( Gould, 1846 )
1. Animal	Eyes visible	Eyes visible	Eyes visible
2. Shell
- Internal/ external	External	External	External
- Shape	Subcylindrical; widest part between apex and	Cylindrically ovate, narrowed towards both ends;	Cylindrical
middle-line	widest part right below middle-line
- Spire	Sunken	Sunken	Sunken
- Sculpture	Spiral grooves at both ends only (anterior =	Step-like spiral grooves at both ends only (anterior	Spiral grooves at both ends only (anterior
16 – 18, posterior = 14), growth lines indistinct	= 10 – 18, posterior = 7 – 13)	= 17 – 18, posterior = 14 – 20), fine
longitudinal growth lines throughout shell
- Umbilicus	Absent	Absent	Absent
3. Jaws	Crescent shape, jaw rodlets with 6 – 8 denticles	Crescent shape, jaw rodlets with 5 – 6 denticles	Crescent shape
4. Radula
- Formula	30 – 42 x 10 – 9.2.1.2.9 – 10	20 – 30 x 12 – 8.1.1.0.8 – 12	27 x 12.1.1.0.12
- Median tooth	Broad base, sharp triangular central cusp,	Broad base, triangular central cusp with thinner	Broad base, triangular central cusp with
pseudo triangular lateral cusp	membrane-like structure on both sides, pseudo	thinner membrane-like structure on both
lateral cusps	sides, pseudo triangular cusp
- Inner lateral tooth	Hook-shaped, triangular base with slight semi-	Present only at right side, hook-shaped, broad base	Present only at right side, hook-shaped,
circular projection outwardly, groove along	with semi-circular projection outwardly, strong	broad base with semi-circular projection
outer margin	denticulation along outer margin	outwardly, strong denticulation along outer
margin
- Outer lateral teeth	Hook-shaped, slender, broad base, broad	Hook-shaped, slender, broad base with semi-	Hook-shaped, slender, with semi-circular
semi-circular projection outwardly, grooves	circular projection outwardly, groove along the	projection outwardly, groove along the
along both outer and inner margins	outer margin	outer margin
5. Gizzard plates
- Structure	10 transverse ridges on each side of pseudo-	8 – 11 transverse ridges, pseudo-rachis present,	8 – 9 ridges
rachis, ridges crescent shape	sometimes nearly absent.
- Sculpture	Tiny rods with pointed tips	Tiny rods with pointed tips along top edge of	Tiny rods with pointed tips at both anterior
ridge, smaller rods with pointed tips at both	and posterior sides of ridges, higher
anterior and posterior sides of ridges	density of rods at anterior half of plate;
posterior half lacks rods on posterior side
of ridges
- Gaps between ridges	Smooth	Smooth	Smooth
6. Male reproductive system
- Prostate	Elongated, three-lobed	Elongated, bilobed, striation present	Elongated, semi-translucent, faint
striations at distal end, division into lobes
not evident
- Seminal duct	One; broad	Two; coiled distally nearly prostate	Two; first seminal duct originates distally
at a pouch close to prostate
- Penial region	Semi-translucent	Translucent	Elongated, semi-translucent
7. Ecology	Sandy bottom below 15 m deep; reef flat	Sandy bottom and Halimeda beds between 6 – 18 m	Shallow areas up to 18 m deep
deep
8. Key references	Pilsbry (1895)	Pease (1868)	Pilsbry (1895)

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.