Comprehensive Description
(
anglais
)
fourni par Smithsonian Contributions to Zoology
Blenniella chrysospilos (Bleeker)
Salarias chrysospilos Bleeker, 1857a:66 [Amboina; lectotype RMNH 4788 designated below].
Salarias coronatus Günther, 1872:424 [Saloman Islands; holotype BMNH 1871.3.29.42].
Salarias belemites De Vis, 1884:695 [Queensland Coast; holotype QM 1.224].
Alticus evermanni Jordan and Seale, 1906:422 [Apia; holotype USNM 51789].
Salarias bryani Jordan and Seale, 1906:427 [Apia; holotype USNM 51794].
Salarias aureopuncticeps Fowler, 1946:179 [Aguni Shima, Riu Kiu Islands; holotype ANSP 72050].
Salarias unimaculatus Aoyagi, 1954:215 [Ishigaki Island; Kowan, Okinawa-Honto; three syntypes, all apparently lost].
Salarias chrysospilus Chapman, 1951:290; Bleeker, 1983:14, 20, pl. 444: fig. 8 [misspelling].
Istiblennius chrysospilos insulinus J.L.B. Smith, 1959:243 [Aldabra; holotype RUSI 244].
DESCRIPTION.—Dorsal fin (Table 20). XII to XIV, 18 to 22 = 31 to 35 (XIII, 19 to 21 in 96% of specimens); mean numbers of total elements slightly higher for males from any locality than for females from same locality (higher for all 14 localities for which means for both sexes are available, but statistically significantly higher for only 1 locality—Queensland, essentially the southern Great Barrier Reef); membrane between spinous and segmented-ray portions incised – length first segmented ray; membrane from posteriormost ray attaching to point on dorsal margin of caudal peduncle just anterior to caudal-fin base.
Anal fin (Table 20). II,20 to 23 (20 to 22 in 97% of specimens); mean numbers of segmented rays tending to be slightly higher in males from any locality than for females from same locality (higher for 12 of 14 localities for which means for both sexes are available; statistically significantly higher for 4 of the 12 localities); posteriormost ray split through base in 44% of specimens, not bound by membrane to caudal peduncle in all but 1 specimen. Some large and/or mature males with skin covering anal-fin spines and distal half of anterior segmented rays slightly inflated or expanded laterally, never crinkled along edges.
Table 20.—Frequency distributions for certain meristic characters in male and female specimens of Blenniella chrysospilos from various localities. Underlining indicates significant differences between means of sexes from same locality (p ≤ .05).
Pectoral-fin rays 12 to 15, 14 bilaterally in 95% of specimens, at least unilaterally in 98% (1 specimen with 12/13, 3 with 15/15).
Pelvic-fin segmented rays 3.
Caudal-fin elements. Total (dorsal + ventral) procurrent rays 11 to 18 (14 to 16 in 91% of specimens); segmented rays 13.
Vertebrae (Table 20) 11 to 13+25 to 28 = 37 to 40 (12 precaudal vertebrae in 99% of specimens; 26 or 27 caudal vertebrae in 93% of specimens); mean number of total vertebrae tending to be higher for males from any locality than for females from same locality (higher for 9 of 14 localities for which means for both sexes are available; statistically significantly higher for only 1 of the 9 localities); posteriormost pleural rib on 12th or 13th from anteriormost centrum (13th in 74% of specimens; Table 21); posteriormost epineural on 25th to 31st from anteriormost centrum (rarely on 25th or 31st; on 27th to 30th in 95% of specimens; Table 21).
Cirri. Nape modally with single, small cirrus on each side, frequently missing unilaterally or bilaterally. Orbital cirrus consisting of elongate basal section with distal end branching into 2 to 11 tiny filaments (usually with 2 to 4; simple bilaterally in 3% and unilaterally in 15% of specimens; 9 or 11 distal cirri in only 2 of 240 specimens examined). Nasal cirri short, palmate, rarely with more than 6 free tips.
Lateral line. Continuous canal anterodorsally with 1 to 25 vertical pairs of pores (varying with population, Table 21), extending posteriorly to point between verticals from bases of 9th and 12th dorsal-fin spines, ending there or continuing posteriorly and ventroposteriorly along body midline as series of 0 to 7 (usually 1 to 4) bi-pored canals (tubes) in skin to point no further posteriorly than vertical from base of third segmented dorsal-fin ray. Mandibular pores 6 (rarely 5, and only unilaterally).
Up to at least 11 (usually 9 or more) sensory pore positions between 1 and 5 o'clock on postorbital margin; 2 to 5 (usually 4 or 5) positions occupied by pairs or multiples of pores.
Posterior dentary canines present in both sexes (rarely absent).
Ventral margin of upper lip crenulate medially; crenulae becoming weak or absent laterally; dorsal margin of lower lip entire. Crest on head of large, adult males consisting of low, longitudinal, fleshy fold or ridge originating anteriorly at level of posterior edge of interorbital space; large females often with very low, longitudinal ridge on nape.
Color pattern (in preservative). Males (Figures 28a, 29a). Two basic forms, dark and pale, with considerable variation within each, probably the result of preservation and handling. Dark form (Figure 28a): body generally brown with tan area ventrally and, sometimes, dorsally; small, dark or pale spots (or narrow stripes, western Indian Ocean specimens) cover posterior half to two-thirds of body; pupil-sized, black spot (rarely 2 spots) in middle of body below first few segmented dorsal-fin rays (usually absent on western Indian Ocean specimens); anterordorsal half of body with scattered small, dark spots. Pale form (Figure 29a): body with series of alternating dark and pale bars, with dark bars occasionally restricted to dorsal half of body; spotting pattern overlying bars similar to that of dark form. Head (both forms): narrow, dark bar usually crossing head behind eyes, followed posteriorly by wide, pale bar bordered posteriorly by another narrow, dark bar, which crosses nape immediately anterior to dorsal-fin origin; small, pale or dark spots variously scattered over head and branchisostegal membranes, which may be barred, spotted, or mixture of both; pigment of ventral portion of dark bar immediately posterior to orbit intensified as contrasting, often crescent-shaped, dark spot, typically persisting in preservative even when remainder of bar not evident; background pattern on head often bicolored, tan over dorsal half, whitish over ventral half. Pectoral-fin base with broken bar, best developed ventrally; fin either spotted (Pacific) or more or less plain dusky (western Indian Ocean). Each dorsal-fin spine usually with black spot at tip; remainder of spinous dorsal fin dusky with small, dusky spots and/or faint, diagonal streaks; segmented-ray portion of fin with basal half to covered with dark reticulations and spots, distal half pale, often with faint, slender, diagonal streaks. Anal fin more or less uniformly dark. Pelvic fin dusky. Caudal fin: ventral half dusky, dorsal half mostly pale with dusky margin.
Females (Figures 28b, 29b). Similar to pale-form males, except: dark bars on body irregularly H-shaped with ventral legs of H distinct, separated by pale area; bars usually formed by, or include, small, black spots (Figure 29b); crossbar and adjacent middle part of H often lacking, resulting in series of vertically paired blotches or spots; black pupil-sized spot on midside of body below anterior segmented dorsal-fin rays usually lacking, poorly developed when present; dorsal fin with distinct, small, black spot usually present near base of every second to fourth element, segmented rayed portion of dorsal fin pale or dusky with faint, dark spots and slender streaks; anal fin dusky with dark distal margin.
Fresh coloration. Smith (1959, pl. 16-4, 16-5; Aldabra) published colored illustrations of fresh female and male. Randall (1992b, fig. 314, Maldives) published a colored illustration of a fresh male. Allen and Swainston (1988, pl. 56-851; Western Australia) and Allen (1985, fig. 387, Kendrew Island) published colored illustration and underwater photograph, respectively, of females. Masuda et al. (1984, pl. 269 A,B) published photographs of fresh male and female specimens from Japan. Underwater photographs of live specimens were published by Myers (1989, pl. 115-A; male; Guam) and Randall et al. (1990:383, female; Great Barrier Reef). R. Winterbottom provided us with a photograph of fresh male from Comoros and G. Allen a photograph of a fresh male from Cocos-Keeling. J. Randall provided photographs of living specimens from Fiji (female) and Bougainville Reef, Coral Sea (male), and fresh specimens from Kendrew Island (male and female), Fiji (female), Samoa (female), and Enewetak, Marshall Islands (males; one photograph published in Burgess and Axelrod, 1973, fig. 375). One of us (JTW) photographed fresh male at the Loyalty Islands and male and female at Rotuma.
Males from Comoros and Aldabra have head olive with small, red spots on snout, becoming orange on opercle; ventral and posteroventral edges of orbit and upper end of preopercle with black spots, each of which has iridescent-blue crescent along posteroventral margin; body olive with about 7 or 8 longitudinal stripes extending from beneath appressed pectoral fin to caudal-fin base; proximal half of dorsal fin with reddish spots and reticulations, spots becoming pale yellow on distal portion of segmented rays. The Maldives male is similar to previous males, but ventral half of head pale with oriange spots, only 2 regular and 2 or 3 irregular orange stripes on body. Males from Cocos-Keeling, Kendrew Island, and all Pacific localities lack orange stripes and have pale-greenish head and body that are abruptly paler on their ventral halves, giving slightly bicolored appearance; small, orangish-tinted, tan spots present on head and body anteriorly; posterior half of body with small, round to dorsoventrally depressed, pale-blue spots; dorsal fin with reticulate pattern of brown streaks and pale-greenish spots basally, reticulations becoming red, merging into yellow-edged distal margin on segmented-ray portion of fin.
Table 21.—Frequency distributions for certain characters in specimens of Blenniella chrysospilos from various localities. A = absent, P = present, S = spotted, U = unspotted. Underlining indicates significant difference between frequency distributions for males and females from same locality (p < .05).
Colored illustration of Aldabra female specimen shows olive ground color with orange spots on head and body, spots on body large, oval shaped; 2 orange spots posterior to orbit each with dark-blue, crescent-shaped posterior margin; all vertical fins yellowish with scattered reddish spots on spinous dorsal fin, row of reddish spots suprabasally on the segmented-ray dorsal fin. Females from Western Australia, Great Barrier Reef, and Fiji have pale body with only slight greenish tint; spots on head and body about same size; spots on head and anteriorly on body orangish brown, those posteriorly becoming brown; distal border of spinous dorsal fin edged in white between black-tipped spines.
Pupil of the eye in all specimens incorporated in pair of orange bars, separated by narrow, pale-blue area; iris pale-blue dorsal and ventral to orange bars.
Size. Largest male 114 mm SL, largest female 97 mm SL, smallest specimen, 24 mm SL. No ophioblennius-stage specimens known.
GEOGRAPHIC VARIATION (Tables 20, 21).—Meristic, color-pattern, and lateral-line pore characters in Blenniella chrysospilos vary considerably geographically. Specimens from neighboring groups of localities may be generally or almost completely recognizable from specimens at other localities based on one or more characters. The geographic distribution of other characters, however, may conflict with such recognition, and there are varying degrees of overlap in most characters between groups of localities. Cocos-Keeling appears to be an area of transition for meristic and some color-pattern characters. Specimens from Cocos-Keeling tend to be intermediate between the low counts in the western Indian Ocean and the high counts in the Pacific. Because of intermediacy and overlaps in characters, we do not believe that nomenclatural recognition of specimens from any grouping of localities is warranted.
Specimens from western Indian Ocean localities (east Africa east to the Maldives) are almost completely distinguishable from those from more eastern localities in having an unspotted pectoral fin and low numbers of vertical pairs of lateral-line pores (Table 21). Western Indian Ocean specimens also tend to have the lowest means for all 5 meristic characters (total dorsal-fin elements, segmented anal-fin rays, total vertebrae, pleural ribs, and epineurals).
The clustering of specimens from western Indian Ocean localities is similarly indicated by the state of the midlateral body spot, whether present or absent. The spot is absent in all males from the western Indian Ocean, except those from Seychelles, in which it is present in 40% of the males. The spot is present in 53% of the males from Cocos-Keeling, eastern Indian Ocean, and in 98% (102 of 104) of males from localities east of Cocos-Keeling. The Seychelles and Cocos-Keeling are transitional areas where males are almost equally likely to have or lack the spot. Females show a different, but similar, distribution of the body spot. The spot is absent in 64 of 66 (97%) females from localities extending from the eastern Indian Ocean to the Philippines, but is present in 9% to 62% of the females from any locality east and south of the Philippines, except for the only 2 females from the Mariana Islands and the only female from Irian Jaya, which all lack the spot.
Although live coloration of males is known for only 2 western Indian Ocean localities, they differ from males from other localities in having distinctive orange pinstripes on the body. Female coloration does not exhibit geographic variation.
A second pattern, though less pronounced, is discernible from the meristic data. The male specimens from Palau, Philippines, and Marshall Islands have low meristics, more similar to those of western Indian Ocean localities than to those of neighboring western Pacific localities. Among males, Palau specimens completely overlap western Indian Ocean specimens (except those from Madagascar) in dorsal-fin, anal-fin, and vertebral counts. The pattern of variation wherein western Indian Ocean and Caroline-Marshall islands specimens have similar meristic counts is reflective of the pattern for B. gibbifrons (although the intermediate eastern Indian Ocean-western Pacific component is lacking for B. gibbifrons). In both groups, these areas tend to exhibit greater agreement with each other than either does with its closest neighboring populations.
In general, means for meristics are highest for specimens from Fiji, which is in an area where means generally tend to be high for populations of species of Blenniella and Istiblennius that occur there.
ECOLOGY.—Blenniella chrysospilos dwells in shallow water on reef crests or fringing reefs. It appears to prefer a high-energy surge environment on exposed reefs.
COMPARISONS AND RELATIONSHIPS.—(See this section under Blenniella gibbifrons). Blenniella chrysospilos is most easily distinguished from all other Blenniella and Istiblennius species by the presence of black-tipped dorsal-fin spines.
DISTRIBUTION (Figure 64).—Known from the Society Islands in the south-central Pacific to the east coast of Africa, and from the Riu Kiu Islands in the north to about 24° S latitude in the Pacific and Indian oceans.
Seale (1906:86), followed by Fowler (1928:437), reported Salarias coronatus Günther (a junior synonym of Salarias chrysospilos Bleeker) from Nukuhiva, Marquesas Islands, based on two specimens. Seale's specimens, however, are identifiable as Blenniella paula (one of Seale's two specimens is now ANSP 81989). Chapman (1951:308), who did not see Seale's specimens, appears to have based his report of Salarias chrysospilos from Nuku Hiva on Seale and Fowler's reports. Blenniella chrysospilos is not known from the Marquesas.
NOMENCLATURAL
- citation bibliographique
- Springer, Victor G. and Williams, Jeffrey T. 1994. "The Indo-West Pacific blenniid fish genus Istiblennius reappraised : a revision of Istiblennius, Blenniella, and Paralticus, new genus." Smithsonian Contributions to Zoology. 1-193. https://doi.org/10.5479/si.00810282.565
Comprehensive Description
(
anglais
)
fourni par Smithsonian Contributions to Zoology
Istiblennius insulinus (see Istiblennius chrysospilos insulinus)
Salarias interruptus Bleeker, 1857b:68
Blenniella interrupta
Salarias kellersi Fowler, 1932:6
Istiblennius bellus
Salarias kingii Valenciennes in Cuvier and Valenciennes, 1836:334
Istiblennius lineatus
Entomacrodus leopardus Fowler, 1904:554
Blenniella leopardus
Salarias leopardus Fowler, 1938:82
Istiblennius bellus
Salarias lineatus Valenciennes in Cuvier and Valenciennes, 1836:314
Istiblennius lineatus
Salarias lividus Thiollière in Montrouzier, 1856:463
Istiblennius lineatus
Salarias marcusi Bryan and Herre, 1903:136
Istiblennius edentulus
Salarias martini Herre, 1942:2
Istiblennius colei
Salarias mccullochi Fowler and Bean, 1923:25
Istiblennius lineatus
Salarias melanocephalus Bleeker, 1849:18
Istiblennius edentulus
Salarias meleagris Valenciennes in Cuvier and Valenciennes, 1836:332
Istiblennius meleagris
Salarias muelleri Klunzinger. 1880:388
Istiblennius muelleri
Salarias multilineatus Fowler, 1945:68
Istiblennius lineatus
Salarias muscarus Snyder, 1908: 109
Blenniella periophthalmus
Alticus novemmaculosus Snyder, 1908:107
Blenniella bilitonensis
Salarias olivaceus Blyth, 1859:271
Istiblennius dussumieri
Salarias oryx Ehrenberg in Cuvier and Valenciennes, 1836:335
Istiblennius rivulatus
Blennius pardalis Castelnau. 1875:26
not Istiblennius
Salarias paulus Bryan and Herre, 1903:136
Blenniella paula
Salarias percophthalmus Swainson, 1839:274 [misspelling]
Blenniella periophthalmus
Salarias periophthalmus Valenciennes in Cuvier and Valenciennes, 1836:311
Blenniella periophthalmus
Salarias periophthalmus visayanus Herre, 1934:97
Blenniella bilitonensis
Salarias personatus Fowler, 1945:71
Istiblennius zebra
Istiblennius pox Sprinqer and Williams, present study
Istiblennius pox
Salarias quadricornis Valenciennes in Cuvier and Valenciennes, 1836:329
Istiblennius edentulus
Salarias quadricornis status coloratus Klunzinger, 1871:488
inactnissible name
Salarias quadricornis status hyalinus Klunzinger, 1871:487
inadmissible name
Salarias quadricornis status transiens Klunzinqer, 1871:488
inadmissible name
Salarias quadricornis status unitus Klunzinger, 1871:488
inadmissible name
Salarias rechingeri Steindachner, 1906:1411
Istiblennius edentulus
Blenniella rhessodon Reid, 1943:383
Blenniella gibbifrons
Salaris [sic] rivulatus Rüppell, 1830:114
Istiblennius rivulatus
Istiblennius rodenbaughi Schultz and Chapman, 1960:358
Blenniella gibbifrons
Salarias rutilus Jenkins, 1903:509
Blenniella gibbifrons
Salarias saltans Jenkins, 1903:508
Blenniella gibbifrons
Salarias schultzei Bleeker, 1859b:345
Blenniella periophthalmus
Salarias siamensis H.M. Smith, 1934:320
Istiblennius dussumieri
Salarias sindonis Jordan and Seale, 1906:427
Istiblennius edentulus
Istiblennius spilotus Sprinqer and Williams, present study
Istiblennius spilotus
Salarias steindachneri Pfeffer, 1893a:143: 1893b:15
Istiblennius steindachneri
Istiblennius steinitzi Lotan, 1970:367
Istiblennius flaviunbrinus
Scartichthys stigmatopterus Fowler, 1904: 553
Istiblennius dussumieri
Salarias striatomaculatus Kner and Steindachner, 1866:368
Istiblennius dussumieri
Salarias striolatus Day, 1876:333
Blenniella cyanostigma
Salarias sumatranus Bleeker, 1851:256
Istiblennius edentulus
Blennius truncatus Forster, 1844:231
Istiblennius edentulus
Salarias tubuensis Seale, 1906:87
Blenniella paula
Salarias unicolor Rüppell, 1838:136
Istiblennius unicolor
Salarias unimaculatus Aovagi, 1954:215
Blenniella chrysospilos
- citation bibliographique
- Springer, Victor G. and Williams, Jeffrey T. 1994. "The Indo-West Pacific blenniid fish genus Istiblennius reappraised : a revision of Istiblennius, Blenniella, and Paralticus, new genus." Smithsonian Contributions to Zoology. 1-193. https://doi.org/10.5479/si.00810282.565