46 research outputs found

    Rotenone stations

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    21 p. : ill. ; 24 cm.Includes bibliographical references (p. 21)."Fish populations of 10 shallow-water stations were sampled repeatedly using small quantities of emulsified rotenone. Taking small samples is not unduly destructive and a complete kill is never obtained. Sampling errors appear to be random. Analysis of the collections indicates that approximately 75 percent of the species present are taken in a single sampling. Repopulation begins immediately and the effects of the sampling disappear four to nine months later. Repeated samplings can be used for Leslie-Davis population estimates. Resemblance indexes for samples from the same and different stations show that each area has a specific array of resident species. Transient species are less consistent in their occurrence. Sampling errors make it difficult to distinguish between transient and low-density resident species"--P. [1]

    Serranid fishes

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    20 p. : ill. ; 24 cm.Includes bibliographical references (p. 18-20)."Serranid fishes exhibit several types of hermaphroditism. 2. Members of the genus Serranus, and its relatives Hypoplectrus, Diplectrum, and perhaps others, are synchronous hermaphrodites, with the gonad divided into separate male and female zones. There are separate ducts for the eggs and sperm. 3. Members of the genera Epinephelus, Mycteroperca, Alphestes, CephalophoIis, and Petrometopon are protogynous hermaphrodites in which the presumptive testicular tissue is scattered as crypts throughout the epithelial layer of the ovarian lamellae. Precocious sperm are formed in some crypts during the juvenile and female phases. Transformation to the male phase is accomplished by proliferation of these crypts, accompanied by the development of sperm sinuses in the gonad wall. The ovarian lumen remains in the male phase, but there is a separate sperm duct. 4. The genus Rypticus has a type of sexuality intermediate between that of Epinephelus and that of Serranus. Rypticus is a protogynous hermaphrodite, with male tissue confined to narrow bands on each side of the oviduct. Male and female elements are intermingled in this region. 5. Although the sexual pattern of Rypticus is intermediate between that of Serranus and that of Epinephelus, it is unlikely that it gave rise to Epinephelus. Rather, Rypticus must be regarded as a specialized derivative of an intermediate ancestor. 6. Hermaphroditic serranids have the acinus type of testes. Gonochoristic Serranidae of the genus Roccus have testes of the radial type. The spermatogonia line connective tissue tubules which radiate from the sperm duct. Their relationship to the marine Serranidae, on the basis of this evidence, does not seem to be particularly close"--P. 17-18

    American groupers

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    p. 69-241 : ill., maps ; 27 cm.Includes bibliographical references (p. 228-241)."The American species of groupers constitute a block of serranid fishes which have been studied as a unit. Field investigation of their biology and life colors has supplemented laboratory studies on morphology, variation, and geographic distribution as indicated by existing museum specimens and literature records. Keys to the genera and species are given and previous literature is summarized in a synonymy for each species. 2. The groupers are moderate-sized to large-sized serranid fishes of warm seas. Most are solitary, reef-dwelling carnivores. In some areas they are the object of intensive, but local, commercial fisheries. Spawning takes place in the winter to late spring, depending on the latitude, but the manner of spawning is not known. The eggs are small, buoyant, and numerous. All of the species so far studied are protogynous. There is a pelagic larval stage during which the groupers can traverse great distances, but the adults are rather sedentary and probably rarely stray far from coral or rock reefs. 3. Groupers undergo considerable color variation of three types: 'instantaneous,' under nervous control; bathymetric, correlated with the environment, some species having strikingly different deep-water and shallow-water color phases; and xanthic, a yellow color phase under genetic control that characterizes small parts of the populations in a few species. A juvenile color phase different from that of the adult is present in some, but not all, species. 4. Osteological characters are useful in grouper classification and the osteology of Epinephelus guttatus is described in detail as a basis of comparison. 5. Subfamily names are not used in this report because present knowledge does not permit compartmentalization at that level. 6. The genus Paranthias is considered monotypic, with allopatric western Atlantic and eastern Pacific populations. 7. Twenty-one American species of Epinephelus are recognized. Seven distinct lines seem to be present. The nominal genera Cephalopholis, Petrometopon, Alphestes, Dermatolepis, Promicrops and Garrupa are placed in the synonymy of Epinephelus. Epinephelus niphobles is a synonym of E. niveatus, which thus has Atlantic and Pacific populations. Other species that occur on both sides of the Isthmus of Panama are Epinephelus nigritus, itajara, and probably mystacinus although the only Pacific record seems to be a small specimen from the GalĂĄpagos and this could be a locality error. 8. Two American species of the subgenus Dermatolepis are well differentiated, one on each side of the Central American Isthmus. 9. The eastern Pacific species previously known as Cephalopholis acanthistia is clearly a member of the E. niveatus species-group. 10. The transverse skull crests of Petrometopon are not sufficient grounds for recognizing it at either the generic or subgeneric levels. It is combined with Cephalopholis as a subgenus of Epinephelus. 11. Epinephelus afer occurs in the Pacific Ocean as well as in the Atlantic; E. multiguttatus is confined to the eastern Pacific. Apparently the subgenus Alphestes has twice invaded the eastern Pacific from the western Atlantic. 12. Thirteen species of Mycteroperca are recognized. These fall into two species-groups. 13. Some proportional measurements are relatively constant among most species of groupers. Others provide good generic and species-group characters and a few furnish useful species characters. Tables of measurements are given for each species except Mycteroperca prionura and M. cidi. 14. Barriers to dispersal and methods of transport of groupers are discussed. Three centers of distribution seem apparent: the eastern Pacific, the Gulf of Mexico, and the West Indies. There is a sharp faunal break across the Straits of Florida and the Gulf Stream seems to be an effective, although incomplete, barrier. There appear to be several levels of differentiation between species in these regions. These may be due in part to different rates of evolution, but are more probably a reflection of different periods of isolation. The last closure of the Middle America gap was late Pliocene and four species remain unchanged since that time. 15. A phylogeny of the American groupers is proposed that is based on the information available at this time"--P. 226-227

    Gobiid fish

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    10 p. : ill. ; 26 cm.Includes bibliographical references (p. 10).The bluenose goby, Coryphopterus lipernes Böhlke and Robins, was described in 1962 from three specimens collected in the Florida Keys; it has remained poorly known since that time. Recent collections and observations indicate that this species is widespread in the caribbean and Bahamas but at low population densities wherever it occurs. It is also one of the few species of western Atlantic reef fishes that lives in relatively continuous close physical contact with live corals. All the individuals, observed at night and during the day, spent most of the time resting on live corals, with only a few brief forays onto nearby algal mats, or off the coral to feed. In this respect the bluenose goby is an ecological counterpart of the Indo-Pacific clownfishes (Amphiprion). The mechanism by which the bluenose goby avoids being stung by the nematocysts of the coelenterates may not be the same as that of the clownfishes because clownfishes become acclimated to individual anemones, whereas the bluenose goby can move freely back and forth among coral colonies of both the same and different species. Other species of fishes associated with live corals in the West Indies share with the bluenose goby certain features that we interpret to be specializations for this way of life. Within the genus Coryphopterus, two divergent lineages show progressive specialization toward coral-dwelling, on the one hand, and toward sand-dwelling, on the other

    Oral brooding

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    11 p. : ill. ; 24 cm.Includes bibliographical references (p. 10-11)."Two specimens of Cheilodipterus affinis Poey from the Bahamas have darkly pigmented, fleshy, protuberant chin flaps. One of these was sectioned and compared histologically with the tip of the mandible from a specimen without the flap. The flap seems to be the result of an increased amount of loose, collagenous connective tissue and histologically bears a strong resemblance to the pharyngeal pads of the mouthbrooding cichlid, Geophagus jurupari. Ten additional specimens with chin flaps have been found in trawl collections made off the coast of Venezuela. This cardinalfish is an oral brooder: eggs have been found in the mouths of seven males and three females. Two of the females and all of the males with eggs in their mouths had chin flaps, but one female without a flap was carrying eggs"--P. 10

    Single-male paternity in coelacanths

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    Latimeria chalumnae, a ‘living fossil,’ is of great scientific interest, as it is closely related to the aquatic ancestors of land-living tetrapods. Latimeria show internal fertilization and bear live young, but their reproductive behaviour is poorly known. Here we present for the first time a paternity analysis of the only available material from gravid females and their offspring. We genotype two L. chalumnae females and their unborn brood for 14 microsatellite loci. We find that the embryos are closely related to each other and never show more than three different alleles per locus, providing evidence for a single father siring all of the offspring. We reconstruct the father’s genotype but cannot identify it in the population. These data suggest that coelacanths have a monogamous mating system and that individual relatedness is not important for mate choice

    New morphological information on, and species of placoderm fish Africanaspis (Arthrodira, Placodermi) from the Late Devonian of South Africa

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    Here we present a new species of placoderm fish, Africanaspis edmountaini sp. nov., and redescribe Africanaspis doryssa on the basis of new material collected from the type locality of Africanaspis. The new material includes the first head shields of Africanaspis doryssa in addition to soft anatomy for both taxa. Hitherto Africanaspis was entirely described from trunk armour and no record of body and fin outlines had been recorded. In addition the first record of embryonic and juvenile specimens of Africanaspis doryssa is presented and provides a growth series from presumed hatchlings to presumed adults. The presence of a greater number of juveniles compared to adults indicates that the Waterloo Farm fossil site in South Africa represents the first nursery site of arthrodire placoderms known from a cold water environment. The preservation of an ontogenetic series demonstrates that variation within the earlier known sample, initially considered to have resulted from ontogenetic change, instead indicates the presence of a second, less common species Africanaspis edmountaini sp. nov. There is some faunal overlap between the Waterloo Farm fossil site and faunas described from Strud in Belgium and Red Hill, Pennsylvania, in north America, supporting the concept of a more cosmopolitan vertebrate fauna in the Famennian than earlier in the Devonian

    Two new clinid blennies (Malacoctenus) from Puerto Rico

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    http://deepblue.lib.umich.edu/bitstream/2027.42/57023/1/OP585.pd
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