Saipan Dwarfgoby

Dorsal spines (total): 7; Dorsal soft rays (total): 9 - 10; Analspines: 1; Analsoft rays: 7 - 8

Inhabits tidepools of exposed seaward reefs (Ref. 37816).

Inhabits tide pools of exposed seaward reefs (Ref. 37816).

Eviota saipanensis Fowler

Eviota saipanensis Fowler, 1945:66, figs. 8, 9 [type-locality: Saipan Island, Marianas Islands].

MATERIAL EXAMINED.—221 specimens from 5 localities totaling 108 males, 73 females, 40 juvenile and unsexed specimens; total size range 6.9–26.3; largest male 26.3, largest female 22.0; smallest gravid female 11.5.

Holotype: ANSP 71594, (14.6), female; Saipan I., Micronesia, Mar-May 1945, E. R. Tinkham.

Other Material: PALAU ISLANDS: CAS 43787, 91 (6.9–20.0), 7 juv., 57 males (20.0), 27 females (16.0); Angaur I., 24 Oct 1957, DeWitt, sta 57–48, GVF Reg. 1428. USNM 218509, 10 (14.2–19.4), 5 males (19.4), 5 females (15.7); same data as CAS 43787. AMS 1.20797-001, 10 (12.6–18.4), 5 males (18.4), 5 females (16.0); same data as CAS 43787. W CAROLINE ISLANDS: CAS 43769, 1 (13.7), female; Fais I., 2 Nov 1956, Scott, sta 212, GVF Reg. 1009. MARIANAS ISLANDS, GUAM: CAS 43757, 9 (13.0–ca. 18.0), 5 males (ca. 18.0), 4 females (13.9); Inarajan, 15 Jul 1956, Gaines and Scott, sta 43, GVF Reg. 829. USNM 219628, 19 (10.3–16.3), 4 unsexed, 8 males (16.3), 7 females (15.2); Tagachan Beach, 14 Jul 1973, H. Larson. UG 5899, 14 (12.5–16.3), 4 males (16.1), 10 females (16.3); Tagachan Beach, 5 Mar 1973, H. Larson. UG 5920, 28 (8.0–15.5), 13 juv. and unsexed, 11 males (15.5), 4 females (13.6); 9 Aug 1972, H. Larson. UG 5895, 31 (7.3–17.9), 16 juv, and unsexed, 10 males (17.9), 5 females (16.4); Tagachan Beach, 19 May 1973, H. Larson. UG uncat., 1 (11.1), female; 4 Oct 1969, R. S. Jones 01041069. TAIWAN: USNM 218510, 6 (12.0–26.3), 3 males (26.3), 3 females (22.0); Mao-Pit'ou, 25 Apr 1969, V. G. Springer, 68-5.

DIAGNOSIS.—Pectoral fin rays 11–15 almost always branched; spinous dorsal fin elongate or filamentous in both sexes; fifth pelvic fin ray absent; genital papilla in males wide, the lateral margins fold inward forming a cuplike structure (Figure 3); subcutaneous bars on posterior trunk number 4, broad and widely spaced; head and trunk lacking prominent color marks; a dark, mostly subcutaneous, spot on midcaudal peduncle over posteriormost subcutaneous bar, about equal to diameter of pupil; a small dark spot on surface, centrally located, at end of hypural plate; fins dusky, the anal fin darkest.

DESCRIPTION.—Dorsal fin VI–I,9(19), VI–1,10(8); anal fin 1,7(1), 1,8(26); pectoral fin 15(1), 16(14), 17(12); pelvic fin 1,4(27); fourth ray of pelvic fin with 7–14 branches, averaging 9.6; segments between the consecutive branches of the fourth pelvic fin ray 1–4, averaging 1.4; pelvic fin membrane reduced; branched caudal fin rays 11(1), 12(12), 13(7), 14(3); segmented caudal fin rays 16(1), 17(26); lateral scale rows 22(1), 23(3), 24(17), 25(5); transverse scale rows 6(2), 7(6), 8(8); breast scaleless. Scales with about 23–34 ctenii, 8–19 primary radii, 1–2 secondary radii.

First 2 dorsal spines of males may be elongate or filamentous, the first spine longest, extending in some to base of eighth dorsal fin ray; first dorsal spine of females may be elongate, extending in some to base of fourth dorsal fin ray; pelvic fin usually not extending to origin of anal fin, but in some it may reach origin of anal fin or extend just beyond it.

The cephalic sensory pore system is pattern 2. Cutaneous papilla system is pattern B, except for a reduced number (only 2–3) of widely spaced papillae in upper lateral cephalic row.

Genital papilla in male broad, slightly fringed at tip, the lateral portions enlarged, somewhat convoluted and folded inward; lateral folds not developed in some small males; females with short, bulbous papilla with fingerlike projections at tip.

Gravid females range in size from 11.5–16.0 mm SL.

Vertebrae 10(12) precaudal and 15(2), 16(10) caudal, total 25(2), 26(10).

COLOR IN PRESERVATION.—Body lacking prominent color marks. The females somewhat more lightly pigmented than the males. Head with large dark chromatophores on cheek, usually clustered into elongate barlike marks, one from eye to rictus, a larger mark from eye to angle of preopercle, and sometimes a small cluster between eye and upper lip; cheek bars may be uniformly shaded in some specimens; scattered chromatophores replace cheek bars in many specimens from the Palau Islands; scattered chromatophores may occur dorsally behind eyes and transcend onto anterior upper opercle; pectoral base usually with fine, scattered chromatophores and occasionally, in both sexes, pectoral base also with a smaller unpigmented elongate area in the dorsal posterior portion; fine speckling also occurs on chin, breast, belly, and laterally on lower three-fourths of trunk, usually reduced posteriorly; trunk shading subtle, and may be absent or barely discernible on some specimens; dorsolateral portion of trunk and predorsal region to occiput abruptly pale, devoid of chromatophores; scale pockets not outlined by dark pigmentation; trunk with 6 widely spaced, broad, subcutaneous bars, 2 on the belly region and 4 from origin of anal fin to end of caudal peduncle, the last bar in line with the midcaudal peduncle spot; bars extend from ventral midline, where they emerge as dark spots, to upper trunk, and do not break up or become irregular in shape in midtrunk region; midcaudal peduncle spot with some surface pigmentation, usually chevron shaped and about the size of the pupil; a very small, dark spot on lateral midline of trunk, at end of hypural plate, present in most specimens, but may be weakly developed or absent, particularly in females from the Palau Islands; all fins except pelvics dark dusky, the anal usually darkest, but in some specimens the dorsal and anal fins may be equally dark; filamentous portion of spinous dorsal fin paler than remainder of fin; spinous dorsal fin of either sex may have 1–5 tiny, dark-centered ocelli on membrane between first and sixth spines; second dorsal fin and anal fin sometimes with weak alternating light and dark spots on outer portions of rays; a narrow pale margin on anal fin; caudal fin rays frequently with alternating dark and light spots, or only dark spots, most highly developed in central portion of fin and more so basally than distally; pectoral fin with dusky membrane, and margins of rays dotted with fine chromatophores; pelvics pale.

GEOGRAPHIC DISTRIBUTION.—Known from Taiwan, Palau, Fais I., Guam, and Saipan (Figure 7).

DISTRIBUTION.—This species is found mainly in the small islands of Oceania occurring from the Palau and Marianas Islands eastward to the Samoa Islands. We also have 2 good collections from the Timor Sea, but a specimen from the Celebes Sea and 2 from Dampier Archipelago, Western Australia, are only tentatively identified (Figure 42).