Elacatinus pridisi Guimarães, Gasparini & Rocha, 2004, sp. n.

Elacatinus pridisi sp. n.

Trindade cleaner goby (Figs. 1–3)

Type series: Holotype: MNRJ 21980, 23.6 mm SL, Enseada dos Portugueses, Trindade Island (20°30'S, 29°20'W), at a depth of 5 m, collected by J. L. Gasparini, 1 April 1999. Paratypes: LBRP 5618 (2 ind., 20.2, 27.8 mm SL, larger a female, smaller undetermined), Enseada dos Portugueses, Trindade Island (20°30'S, 29°20'W), at a depth of 5 m, collected by R. Z. P. Guimarães, 10 October 1998; MBML 593 (2 ind., 20.3, 24.5 mm SL, larger a female, smaller undetermined), MNRJ 21981 (2 ind., 20.2, 20.5 mm SL, undetermined), USNM 365990 (1 ind., 21.0 mm SL, undetermined), collected with the holotype; UFES 1424 (1 ind., 28.4 mm SL, undetermined), ZUEC 5412 (1 ind., 18.1 mm SL, undetermined), Enseada dos Portugueses, Trindade Island (20°30'S, 29°20'W), at a depth of 6 m, collected by J. L. Gasparini, 8th April 2001.

Additional material: LBRP 5618 (1 ind., 27.7 mm SL, c & s), Enseada dos Portugueses, Trindade Island (20°30'S, 29°20'W), at a depth of 5 m, collected by R. Z. P. Guimarães, 10th October 1998.

Comparative material: Elacatinus randalli: ANSP 110672 (1 ind., 21.1 mm SL, holotype), ANSP 110673 (5 ind., 19.0– 27.5 mm SL, paratypes), St. Vincent Islands; ANSP 110679 (1 ind., 27.3 mm SL, paratype), ANSP 110680 (3 ind., 10.5–31.5 mm SL, paratypes), Venezuela; MNRJ 12054 (2 ind., 19.8–23.4 mm SL 122.9 mm SL, c & s), Fernando de Noronha Archipelago. Elacatinus figaro: LBRP 0 494 (3 ind., 21–37.7 mm SL), LBRP 0 728 (7 ind., 24–30.75 mm SL, 2 ind., 24.2–27.5 mm SL c & s), LBRP 3084 (1 ind. 36.7 mm SL), LBRP 3494 (20 ind.26.1–30.0 mm SL), LBRP 3515 (12 ind., 24.7– 30.8 mm SL, 3 ind., 26–28.2 mm SL, c & s), state of Rio de Janeiro, Brazil.

Diagnosis: Elacatinus pridisi n. sp. differs from its congeners of the Horsti Complex (sensu Böhlke & Robins 1968) that have a pale stripe extending from the eye to the caudal­fin base by the following combination of characters: dark longitudinal stripe wide, reaching lower abdomen and base of anal fin (vs. never reaching abdomen or base of anal fin in all other species); pectoral­fin rays typically 18 (vs. typically 17 in E. randalli and E. figaro and typically 16 in E. atronasum (Böhlke & Robins)); anal­fin rays typically 11 (vs.

typically 10 in E. figaro); oval spot present on snout (vs. no spot in E. atronasum and E. horsti (Böhlke & Robins), a "V"­shaped spot in E. prochilos (Böhlke & Robins), and a medial bar in E. xanthiprora (Böhlke & Robins), E. louisae (Böhlke & Robins) and E. lori Colin).

Description. Morphometrics of holotype and four largest paratype specimens (21.0– 28.4 mm SL) as percent of standard length (mean): head length 22.5–24.7 (23.3); snout length 3.7–4.2(3.9); eye diameter 6.0–6.8(6.3); postorbital distance 13.5–14.9(14.3); depth of body at dorsal fin origin 15.5–16.1(15.7); least depth of caudal peduncle 11.0– 12.3(11.4); upper jaw length 6.5–8.4(7.6); pectoral fin length 19.3–20.8(20.0); ventral fin length 17.3–18.3(17.7); caudal fin length 17.1–20.0(17.7); maximum width of color stripe 5.1–6.4(5.8).

Body naked, elongate. Mouth subterminal, no canine teeth on jaws. Dorsal fin without elongated anterior spines. Caudal fin rounded and ventral fin cup complete.

Dorsal­fin rays VII, 11–12 (modally 12); Anal­fin rays 11; pectoral­fin rays 17–18 (modally 18).

Color pattern: a pale (bright yellow in life) stripe extending from the eye to the caudal­fin base, stripe narrower close to eye (more uniform in juveniles); a pale (bright yellow in life) oval spot present on snout; dark longitudinal stripe wide, reaching lower abdomen and base of anal fin; all fin­rays except caudal black or dusky.

Remarks: Elacatinus pridisi differs from the other two Brazilian species of the genus by its higher number of pectoral­fin rays and by its wider extension of its dark pigmentation, reaching the abdomen as well as dorsal and anal­fin rays (Figure 3).

Distribution: The new species was collected only from Trindade Island (20°30'S, 29°20'W), a volcanic formation off southeastern Brazil (Figure 4) and is probably endemic to the Trindade­Martin Vaz oceanic insular complex (Figure 5).

Etymology: The name pridisi is used in honor of the Brazilian Navy First District (Primeiro Distrito Naval, Marinha do Brasil ­ "PRIDIS"), in recognition for the impeccable logistic support provided during the authors´field trips to the type locality.

Natural History: Elacatinus pridisi was recorded at depths ranging from 3 to 30 m over crustose algal reefs and rocky bottoms around Trindade Island. The new species performs cleaning activities during most of its life­cycle, and has, at least, 21 different client species (Gasparini & Floeter, 2001).