Blue Spotted Blenny

Diagnosis: Dorsal fin XII-XIV, 19-22, notched between spinous and segmented-ray portions; anal fin II-III, 20-23 (rarely 23); pectoral rays 12-15 (usually 14); pelvic fin I, 3; caudal fin procurrent rays 10-16, segmented rays 13. Vertebrae 10-12 + 26-29. Last pleural rib on 11-13th vertebrae. Orbital cirrus simple filamentous; nasal cirri short and simple to palmate with 2-7 branches; nape without cirri. Lateral line, continuous anterodorsally below dorsal spines from 6-7th to 10th, disconnected posteroventrally up to below dorsal spine 9-13th. Mandibular pores 3-7 Lips margin entire. Occipital crest present, higher in males (Ref. 9962). Body depth at anal-fin origin 5.8-7.3 in SL. Male crest yellow; body greyish, shading ventrally to white, with 9 brown or olive vertical bars on side, and some horizontal streaks on middle of body (Ref. 90102). Females have numerous longitudinal pinstripes on their sides and black specks on their fins while males have dark patches and small blue spots on their sides (Ref. 37816).

Distinct pairing (Ref. 205).

Dorsal spines (total): 12 - 14; Dorsal soft rays (total): 19 - 22; Anal spines: 2 - 3; Analsoft rays: 20 - 23; Vertebrae: 37 - 40

Occurs in exposed shallow shores, 0-3 m deep (Ref. 90102).

Adults inhabit exposed shallow shores (0-3 m) and often found in tidepools (Ref. 90102). Oviparous. Eggs are demersal and adhesive (Ref. 205), and are attached to the substrate via a filamentous, adhesive pad or pedestal (Ref. 94114). Larvae are planktonic, often found in shallow, coastal waters (Ref. 94114).

Blenniella caudolineata (Günther)

Salarias caudolineatus Günther, 1877:209 [Otaheiti (= Tahiti); lectotype BMNH 1873.4.3.177, designated below].

Salarias beani Fowler, 1928:441 [Faté, New Hebrides; holotype BPBM 1063].

DESCRIPTION.—Dorsal fin (Tables 6 and 7). XII to XIV, 19 to 22 = 32 to 35 (XIII in 97% of 475 specimens examined for character); mean numbers of total elements higher for males than for females for 13 of 16 localities for which means for both sexes are available (statistically significantly higher for 8 of the 13 localities, means identical for 3 localities); membrane between spinous and segmented-ray portions notched to more than length of first segmented ray (usually more than length); membrane from posteriormost ray attaching to point ranging from slightly in advance of caudal-fin base to on dorsal edge of caudal fin (out on fin up to 25% length of fin in males, up to 6% in females, usually no more than slightly posterior to fin base in both sexes).

Anal fin (Tables 6 and 7). II or III,20 to 23 (III in only 3 of 466 specimens examined for this character); mean numbers of segmented elements higher for males than for females from all 16 localities for which means for both sexes are available (statistically significantly higher for 6 localities); posteriormost element usually not split to base (85% of 439 specimens examined for this character), posterior element of split ray often present as nubbin of bone visible only on radiographs; fin bound by membrane to caudal peduncle in only 2 of over 114 specimens examined for this character. Skin covering distal half of anterior segmented anal-fin rays of large or mature males thickened or inflated and weakly crinkled along edges.

Pectoral-fin rays 12 to 15 (14 bilaterally in 90% and unilaterally in 9% of 142 specimens examined for this character).

Pelvic-fin rays I,3.

Caudal fin. Dorsal procurrent rays 6 to 8, ventral procurrent rays 4 to 8 (rarely 4 or 5), total procurrent rays (Table 8) 10 to 16 (14 in 55% of 417 specimens examined for this character; dorsal/ventral rays , , or in 86% of specimens); segmented rays 13 in all 323 specimens examined for this character.

Vertebrae (Tables 6 and 7). 10 to 12+26 to 29 = 37–40 (11 precaudal vertebrae in 404 of 411 specimens examined for this character), mean numbers of total (and caudal) vertebrae usually higher for males from any locality than for females from same locality, higher at 13 of 16 localities for which means for both sexes are available, statistically significantly higher at 5 of the 13 localities); posteriormost pleural rib on 11th to 13th from anteriormost centrum (on 12th in 372 of 376 specimens examined for this character); posteriormost epineural on 21st to 30th from anteriormost centrum (on 24th to 29th centrum in 96% of 320 specimens examined for this character).

Cirri. Nape cirrus absent. Orbital cirrus a simple filament, always shorter than orbital diameter in females, length occasionally equal to or slightly exceeding orbital diameter in males. Nasal cirri short, simple to palmate, with 2 to 7 branches (rarely more than 4 branches; anomalously, one specimen with 8 branches on 1 side, 13 on the other).

Lateral line. Continuous canal anterodorsally with simple pores extending posteriorly to point between vertical from between bases of 6th and 7th dorsal-fin spines to vertical from base of 10th spine (to 10th in only one specimen; extending posterior to vertical from base of 7th spine in 98% of 124 specimens examined for this character), then continuing posteroventrally and posteriorly as series of 1 to 6 short, disconnected, horizontally bi-pored canals (tubes) in skin (2 to 5 in 97% of specimens); posteriormost tube in area between vertical from between bases of 9th and 10th spines and vertical from base of 13th spine (posterior to vertical from 9th spine in 94% of specimens).

Mandibular pores 3 to 7 (Table 8; 6 bilaterally in 88% of 454 specimens examined for this character, and at least unilaterally in 97% of specimens). Six or 7 sensory pore positions between 1 and 5 o'clock on postorbital margin (6 in 97% of 117 specimens examined for this character), 0 to 2 positions occupied by pairs of pores (2 positions in 94% of specimens; no pairs in only 3 specimens).

Posterior canines present in specimens longer than 26 mm SL, variably present in specimens as small as 21 mm SL.

Margins of both lips entire.

Crest. Recognizable crest-like ridge or well-developed blade-like crest present dorsally on head of all male specimens ≥19 mm SL; crest-like ridge occasionally present in males as small as 18 mm; highest crest 2.9 mm. Distinct crests or crest-like ridges present in all female specimens ≥21 mm SL, crests and ridges essentially absent in smaller females, but several sex- indeterminate specimens about 19 to 20 mm SL with definite crest-like ridges, and one 17 mm female with slight ridge; highest crest only 1.3 mm, but most <0.7 mm.

Color pattern (in preservative). Males (Figure 8). Head: variably dusky, without prominent, dark markings at many localities, except commonly with small-to-large, faintly-to-darkly dusky spot dorsally on opercle, and small, faintly-to-darkly dusky, elliptical or almond-shaped spot just posteroventral to orbit; upper lip occasionally with 3 barely recognizable, dusky bands, those at corners of mouth extending posteroventrally onto ventral surface; crest more or less uniformly dusky, often with well-delineated, narrow, pale distal edge. Body: well-preserved specimens with up to 9 dusky bands on midside, 6 or, occasionally, 7 posterior to vertical at dorsal-fin notch; anterior 3 bands and band on caudal peduncle frequently faint or missing; several dusky saddles, often paired and connected to bands, present along dorsal body contour, extending onto dorsal fin basally; each of anterior 4 bands below segmented-ray portion of dorsal fin variably incorporating vertical pair of small, dark ocelli (rarely more than 3 pairs total, with half pair represented by ventral member), ventral member of each pair at or near ventral margin of band, dorsal member usually completely enveloped by band; smaller, additional ocelli occasionally present above dorsal member of each ocelli pair, and at mid-left and mid-right margins of bands; occasionally numerous, tiny, pale spots posteriorly on body, giving speckled appearance to body; occasionally up to 4 short, very fine, faintly dusky pinstripes in region below posteriormost 4 dorsal-fin spines and anteriormost 2 segmented dorsal-fin rays (visible only in well-preserved specimens). Dorsal fin: spinous portion dusky, darker distally, occasionally with interrupted, very fine, dark, distal edge or subdistal stripe and/or pale distal edge; segmented-ray portion irregularly dusky; fine, dark, interrupted pinstripes coursing through basal third of fin, rarely combining with dusky interspace between stripes to form broad, basal stripe. Caudal fin: several faint, fine, dusky spots on each ray of dorsal half (but distal margin unmarked dorsally) forming up to about 6 irregular bands; ventral half dusky with small, pale spots sometimes in membranes between rays. Pectoral and pelvic fins unremarkable.

Color slide of freshly dead male from Rotuma indicates following: most dusky areas on head, body, and vertical fins of preserved specimens represented by shades of brown or greenish brown; faintly blue ocelli on body; numerous small, pale spots present ventrally, between body bands, and covering caudal peduncle; row of large, slender, cream-colored spots just below dorsal body contour; 3 short, dark sections of pinstripes on midside below posterior end of spinous dorsal fin; caudal fin olive-brown with few small, pale spots subdistally and broad, pinkish, distal margin.

Schultz and Chapman (1960, pl. 117: fig. E), as I. cyanostigma, present a black an white illustration of a male.

Females (Figure 9). Head: variably dusky, usually without distinctive marks; small, faintly dusky spot occasionally ventroposterior to orbit; corner of mouth and adjacent area between corner and ventral orbital margin occasionally noticeably pale; crest dusky, often with narrow, pale, distal margin. Body: most noticeable markings consist of 3 or 4 dark pinstripes extending posteriorly from area below 5 posteriormost dorsal-fin spines for varying distances to area below posterior third or fourth of base of segmented-ray portion of fin, there breaking up into numerous dark spots and dashes; only 1 pinstripe below body midline, separated from stripe at body midline by space about twice depth of spaces separating stripes above midline; space between ventral stripe and midline stripe either without markings or with row of well-separated, fine, dark dashes; when only 1 pinstripe exists above midline stripe, interspace between these 2 stripes contains row of dark dashes (Shen, 1984, fig. 392–16a, and Shen et al., 1986, fig. 42a, as Istiblennius cyanostigma, present a photograph of a specimen with only the ventral and midline pinstripes; the 2 stripes dorsal to the midline are broken into long dashes; Myers, 1989:211, fig. 5d, as I. lineatus, provides a good photograph of a more typical female); up to 6 or 7 faintly dusky bands on midside in advance of and underlying dark pinstripes; bands occasionally forked ventrally, with disjunct small, paired saddles along dorsal body contour. Dorsal fin: Spinous portion usually with 1 or 2 rows of dark spots distally and diffuse dusky markings basally, distal dark markings occasionally irregularly shaped; segmented-ray portion with 2 or 3 rows of dark spots centered on rays. Anal fin faintly dusky, darkest distally, row of dark spots often present posterobasally. Caudal fin with up to about 8 irregularly vertical columns of dark spots centered on rays. Pectoral and pelvic fins essentially unmarked, except several specimens from New Hebrides with few fine, dark spots on each pectoral fin.

Size. Largest specimen, male, 82 mm SL, males commonly exceeding 70 mm SL; largest female, 68 mm SL, few females exceeding 55 mm. Smallest specimen, juvenile, sex indeterminate, 14 mm SL. No ophioblennius-stage specimens known.

COMPARISONS AND INTERRELATIONSHIPS.—See this section under Blenniella cyanostigma species account; also Table 5 for comparisons of males with those of similar species.

DISTRIBUTION (Figure 65).—Southern Japan south to Moluccas, east to Marianas Islands, east and south to Tonga, and east to Tuamotu Archipelago; Tarawa, Kiribati (= Gilbert Islands), Howland Island.

NOMENCLATURAL

分布於太平洋區，由日本至東加及土木土群島等。台灣分布於南部、小琉球、綠島及蘭嶼等海域。

小型魚類，僅具學術研究價值。

體延長，稍側扁，似圓柱狀；頭鈍短。頭頂具冠膜，雌魚的較低。鼻鬚2-4絲狀分支，眼上鬚單一不分支，無頸鬚。 上下唇平滑；齒骨具一犬齒。D. XIII-XIV, 19-21； A. II, 21-22；P. 14； V. I, 3。背鰭具缺刻，最後一棘很小，背鰭與尾柄相連，臀鰭不與尾柄相連。雄魚眼眶後下緣、鰓蓋上緣各有一黑點；體側有8-9條淡橫帶，每一橫帶中央有2個鑲黑邊的淡藍點，有3-5條不明顯的斷縱線；背鰭和臀鰭的基部透明，末稍黑色，胸鰭灰白色，尾鰭有4-5條深紋，無白點； 雌魚鰓蓋上緣黑斑不明顯，體側有7-8條淺橫帶，有5條明顯的黑色斷縱線，後端或斷裂成點狀；背鰭基部具一列斑點；胸鰭灰白色；尾鰭有6-7列橫向黑點。以前所記載之紅點蛙鳚(/Istiblennius cyanostigma/)為本種之誤鑑。

主要棲息於潮間帶礁石潮池區，受驚嚇時可見其用一前一後的方式跳躍於潮池與空氣間。以藻類為食。

Blenniella caudolineata, the blue-spotted blenny, is a species of combtooth blenny found in coral reefs in the Pacific ocean.