Notes on the Blennioid Fishes of Hawaii with Descriptions of Two New Species
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Notes on the Blennioid Fishes of Hawaii with Descriptions of Two New Species DONALD W. STRASBURG! ALTHOUGH NEARLY EVERY REPORT on the assemblage, with the major collecting em Hawaiian inshore fishes alludes to the blen phasis being on Oahu, in the windward Ha nies, the Hawaiian members of this group waiian chain. Where synonymies are given have never been reviewed in their entirety. they refer only to Hawaiian records unless Jordan and Evermann (1905) discuss and otherwise noted. figure most of the common forms, while Jordan and Seale (1906) and Fowler and co ACKNOWLEDGEMENTS authors (1901, 1922, 1925, 1928, 1949) pre sent supplemental data. Unfortunately the I am greatly indebted for assistance re taxonomy employed in the above reports is ceived from numerous individuals and insti sometimes inaccurate because of the close tutions. Dr. William A. Gosline and other resemblance between Hawaiian blennies and staff members of the University of Hawaii those of other areas, and in a few instances it aided me in collecting many of the specimens errs because of a species being based on a examined. The Museum of Comparative larval or sexual form. There are overall prob Zoology at Harvard College sent certain early lems of a lack of adequate keys and of generic collections of Hawaiian blennies; Dr. J. 1. B. names not being up to date. Smith loaned. a South African specimen of This paper was prepared with a three-fold Entomacrodus; and Dr. Itiro Tomiyama sup purpose. It attempts to clarify certain nomen plied specimens of several Japanese blennies. clatorial problems, it provides a key and a Drs. N. B. Marshall and Gilbert P. Whitley, description for the identification of each Ha of the British and Australian Museums re waiian species, and it reports two hitherto spectively, examined type material unavail undescribed forms as new, along with a new able to me. I am grateful for permission to record of a previously known species. The examine specimens and use various facilities geographical scope of this study includes the at the United States National Museum, the high or windward Hawaiian Islands, the lee American Museum of Natural History, the ward islets and shoals extending from Niihau Bernice P. Bishop Museum, the University of northwest to Midway Island, Midway Island Hawaii, the Pacific Oceanic Fishery Investiga itself, and Johnston Island. Specimens have tions (u. S. Fish and Wildlife Service, Hono been taken from numerous islands in this lulu), and the Territorial Division of Fish and Game (Honolulu). In this report these in 1 United States Fish and Wildlife Service, Honolulu. Work done at Duke University, Durham, N. C. Manu stitutions are referred to as follows: USNM, script received May 23, 1955. AMNH, BPBM, UH, POFI, and DFG. The 241 242 PACIFIC SCIENCE, Vol. X, July, 1956 Museum of Comparative Zoology at Harvard fin membrane is notched between the spinous College is abbreviated as MCZ. Mr. James and soft-rayed portions, and the minute last K. Park of Honolulu prepared Figure 2. dorsal spine occurs at the base of this notch. In those genera having the dorsal fin entire the last dorsal spine is about the same size METHODS as the penultimate one. The Hawaiian blennioid fishes include rep The anal fin of Hawaiian blennies is com resentatives of the families Blenniidae and posed of two short, weak spines (only one Tripterygiidae. As pointed out by Clark spine in the tripterygiids) followed by a series . Hubbs (1952: 50), these families are readily of longer soft rays. Aside from their length ' distinguishable by the presence of scales in it is practically impossible to distinguish anal the Tripterygiidae and by their universal ab spines from rays without dissection and stain sence in the Blenniidae (except in Neoclinus, ing, and the problem is further complicated which does not occur in Hawaii). In addition in female blenniids where the first spine be to the presence of scales, the three dorsal fins comes embedded in genital tissue with and bright red coloration render the single growth. In adult male Cirripectus and Exallias Hawaiian tripterygiid a readily identifiable each anal spine is enclosed in a mass of form. spongy tissue, the presence of which facili Norman's analysis of the genera (1943), tates sex determination. supplemented by Schultz's definition of Ru The methods employed by Strasburg and nula (1950) and Strasburg and Schultz's' of Schultz (1953: 129) have been used for count Cirripectus and Exallias (1953), constitutes the ing head cirri. A nuchal cirrus was counted basis for generic subdivision of the Hawaiian as one if it had a single base, cirri with distal Blenniidae. The need for dividing certain or basal branches thus being enumerated as heterogeneous genera such as Istiblennius has one. The degree and type of branching of been implied by Norman (op. cit.), but it is supraorbital cirri was found to be useful in ·felt that such separation should be made in distinguishing species of Cirripectus, and the monographic treatments and not in a faunal morphology of these structures is discussed report. The Hawaiian blennies can be sub in the key and species diagnoses. divided into the subfamilies Blenniinae and An important characteristic of some blen Salariinae as shown by Norman (op. cit.), but niids is their possession of canine teeth in it appears that his Ophioblenniinae may rep addition to numerous small incisors. Canines resent only larval forms. range in size from short stubs in Entomacrodus In the following key considerable use has to large fangs in Runula, but are lacking in been made of meristic characters, and the Istiblennius zebra and Exallias. When present, methods used in counting certain structures canines occur posteriorly in the jaws and need explanation. Each fin ray with a separate mesial to the incisors. and distinct base was counted as one, and Many Hawaiian blennies have relatively those rays split to a single base were also large larvae which are considerably different counted as one ray. Spines and soft rays are from the adults. In a few cases such larvae sometimes difficult to distinguish in the Ha have been the basis for the erection of genera waiian blennies, but can often be differen and species, and only recently (Chapman, in tiated when the fin is held before a strong de Beaufort and Chapman, 1951: .249-254) light, or by removing the membrane from one have they been recognized as larval forms. side of the fin . In general, the spines are soft Larvae are readily distinguished from juveniles and flexible but rather more slender than by their glassy transparency when alive and articulated rays . In certain genera the dorsal their nearly uniform straw or white coloration I\.~'''' Blennioid Fishes - STRASBURG 243 in preservative. Identification of larvae usually soft rays posteriorly, the two regions cannot be made with the following key. often separated by a notch in the con necting membrane, and appearing as separate fins (family Blenniidae) . .. 2 DUBIOUS RECORDS 2a. A transverse fringe of from 25 to 45 Jordan and Evermann (1905: 5, 7, 10, 23, cirri across the nape ..... ... ..... 3 497), Fowler (1928: 432), (1938: 300), and 2b. No fringe of cirri across nape; if cirri others have listed Hypsoblennius sordidus (Ben occur on nape they total four or less .. 6 nett) as a valid Hawaiian species. Fowler 3a. Dorsal rays XII, 13 (rarely XII, 12 ); no (1901: 517; 1922: 84; 1928: 428; 1938: 300) canines on dentary; teeth in lower jaw also records Aspidontus filamentosus (Valen more or less rigidly implanted, those in ciennes) from Hawaii but later (1949: 146) upper jaw freely movable; lower teeth changes the name of his specimen to Aspidon about twice as broad and half as numer tus taeniatus Quoy and Gaimard. Fowler ous as those in upper jaw; a pair of (1928: 442; 1938: 301) lists Hawaiian spec stubby tentacles on each side of chin; imens of Istiblennius lineatus (Valenciennes) as with numerous small dark spots on pale being in the United States National Museum, background, spots sometimes arranged but a thorough search by the writer did not in clusters which may align to form reveal the specimens there. Gunther's Ha vertical bars ... ..... Exallias brevis waiian record of Hypsoblennius brevipinnis 3b. Dorsal rays XII, 14 to 16 (very rarely (1861 : 226; 1877: 194) is probably a geo 13); a short stout canine posteriorly on graphica~ error as was pointed out by Jordan dentary; teeth in both jaws freely mov and Evermann (1905: 504), although the able, of approximately equal width and species is not a synonym of Exallias brevis as number; no tentacles on chin; ground indicated by the latter authors (ibid.). Jordan color dark, unmarked, or with light or and Evermann's listing of Scartichthys sauritus dark spots ... ... ... ... .... 4 (1905: 17), which would be a blenny, is a 4a. An elongate dark spot, about size of misspelling based upon Fowler's earlier record pupil, behind eye; dorsal rays XII, 16 (1901: 511) of Scarichthys auritus, a parrot fish. (rarely 15); anal rays usually II, 17; Since none of the above species has been upper part of membrane between an taken in the writer's five years of collecting terior dorsal spines dusky, not abruptly in Hawaii, it is possible that records of their pale or transparent; bases of upper pec Hawaiian occurrence are invalid. They are not toral rays notably darker than bases of considered further in this report, but errone lower rays; head and trunk rosy or red ous records of other species are listed under dish brown, tail dark brown, frequently the appropriate synonymy. with irregular olive or tan blotches; head and body usually covered with scattered white dots ...............