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Calyptospora funduli has a broad host specificity, infecting at least 7 natural and 10 additional experimental definitive hosts, all atheriniform fishes within 5 families, but most in the genus Fundulus. Barriers, apparently innate ones, prevent any development of C. funduli in perciform fishes but allow incomplete or abnormal development of the parasite in a few unnatural atheriniform hosts. In the freshwater species Fundulus olivaceus and Fundulus notti, these abnormalities consisted of asynchronous development, degeneration of the parasite in early stages of development, and the formation of numerous macrophage aggregates. Rivulus marmoratus has the ability to eliminate infections with a granulomatous inflammatory response. Additional barriers that limit natural infections of C. funduli in other hosts include feeding behavior, environmental conditions, and geographic isolation.

The shape of haemal arches of the vertebral column in several species of South American atherinids was analyzed. A large amount of variation was found, from species showing greatly expanded haemal arches connected to one another forming a cone or funnel, to others with completely unexpanded arches. The first case is hypothesized as the specialized (apomorphic) condition within the Atherinidae, on the basis of ontogenetic development.

The age structure, annual growth, length-weight relationship, reproduction and other aspects of the general biology in Boyer's sandsmelt, Atherina boyeri, from the Severn estuary, have been studied for the period 1974–1977. The results are compared with those found in previous investigations of A. boyeri from more southerly waters.

Some populations of one or more species of the goodeid fish genusIlyodon in certain tributaties of Coahuayana and Armeria rivers (.Jalisco and Colima, Mexico) are dichotomous with respect to morphological features that are presumptive trophic adaptations. A narrow mouth ‘morph’ (described asI. furcidens in the Rio Armeria) is sympatric with a broad mouth morph (namedI. xantusi). The morphs are additionally divergent in tooth and gill raker numbers and in coloration of mature males. Other populations are essentially continuous (nondichotomous') in these features.

Critical Catalogue of the Types and Typoides of the Fish Collection of the Zoological Museum Berlin. Part 1: Atheriniformes This paper is the first part of the catalogue of fish types stored at the Zoological Museum of the Humboldt-University of Berlin. It only includes the types of the (old) order of Atheriniformes sensu GREENWOOD, ROSEN, WEITZMAN & MYERS (1966). A short sketch on the history of the fish department as well as some remarks on special problems connected with the collection are given.

The olfactory organs of 6 rainbow fish species were studied, and were compared with those of closely related cyprinodonts. It has been found that, in contrast to cyprinodonts, the olfactory mucosa of rainbow fish is more conspicuously thrown up into folds. Their arrangement in parallel is considered a relatively primitive character of the organ. Electron microscopic investigations on Nematocentris maccullochi have shown that the sensory epithelium consists of basal, supporting, and two types of receptor cells, ciliated and microvillous. As in cyprinodonts the receptor cell cilia exhibit a basic 9 + 0 microtubular pattern. In Nematocentris the frequency of receptor cells, between 200,000 and 250,000 per mm2, is lower than in cyprinodonts. It may be suggested that the lower density is compensated for by enlargement of the sensory area due to the folding. In addition to broad-surfaced dendritic membrane appositions found in both Nematocentris and cyprinodonts, contacts by means of dendritic spines are found only in the rainbow fish. The olfactory supporting cells of the latter are distinguished from those in cyprinodonts by more prominent lateral interdigitations, centrioles, and the higher number of vesicles associated with extensive Golgi complexes.

Significant genic differentiation occurred in samples of a stream population of Goodea atripinnis(Goodeidae) from a 1 km segment of the Rio Teuchitlan, Jalisco, Mexico. The lack of obvious selection gradients and physical barriers to migration over such short distances suggests that stochastic factors (seasonal reductions in stream flow, behavior) are involved in the differentiation. The extent of this phenomenon and its potential importance to the study of fish populations are discussed.

Salsuginus Beverley-Burton, 1984 has been proposed for ancyrocephalid monogeneans found on North American Cyprinodontoidei (Atheriniformes). The genus is distinguished by the following characteristics: penis sclerotized, tubular, spiralling to form single coil; accessory piece with median groove to accommodate shaft of penis, distal point heavily sclerotized; dorsal and ventral hamuli similar in shape with distinct superficial and deep roots and curved blade; dorsal and ventral transverse bars bandlike, bowed posteriorly with posterior notch at extremities of each: larval hooks of similar shape and size with well-developed sickle bearing thumblike projection. Salsuginus angularis (Mueller, 1934) Beverley-Burton, 1984, the type species, is redescribed from the present material found on Fundulus diaphanus (Lesueur) in Ontario. Salsuginus umbraensis (Mizelle, 1938) n. comb., S. funudulus (Mizelle, 1940) Beverley-Burton. 1984. S. seculus (Mizelle and Arcadi, 1945) n. comb. and S. bahamianus (Hanek and Fernando, 1972) n. comb. are transferred from Urocleidus Mueller, 1934; S. spirae (Williams, 1980) n. comb. is transferred from Ancyrocephalus Creplin, 1839. Material found on F. heteroclitus taken in New Brunswick is described as S. heterocliti n. sp. Evolutionary aspects of Salsuginus spp. are briefly discussed and notes on the identification of species parasitizing Fundulus spp. are presented. Previous records of Salsuginus spp. are listed.

The endangered Sonoran topminnow Poeciliopsis occidentalis has steadily declined in distribution and abundance in the past several decades, and currently survives in the United States only in several isolated localities in southern Arizona. This reduction is correlated with, and primarily attributed to, habitat destruction, and introduction and establishment of mosquitofish Gambusia affinis and other exotic fishes. Topminnows have characteristically been reduced in number or replaced within a year or two of introduction of non-native fishes. Other native fishes have experienced similar declines after introduction of exotics, and much of the endemic western ichthyofauna may be vulnerable to extirpation in this manner. Predation by introduced fishes on natives appears to be a likely mechanism of replacement.

Lunar-synchronized spawning has been reported in four orders of fish. Salmoniform, atheriniform, and tetraodontiform species spawn intertidally on spring tides, leaving their eggs exposed to air between tidal inundations. This spawning mechanism may be essential to survival of species that are residents of areas such as tide marshes where dissolved-oxygen concentrations in the water column can be near zero. Spawning cycles of both lunar and semilunar periods have been reported in coral-reef fishes of the Perciformes. Reproduction by these fishes does not include aerial incubation of eggs. It has been hypothesized that the spawning cyclicity in these fishes synchronizes reproduction with moonlight or current conditions that enhance parental care or predator avoidance. The intertidal spawners that have been studied display cyclic changes in gonad maturity consistent with a semilunar periodicity in recruitment of oocytes into final maturation. Oocytes in the early stages of vitellogenesis are presen...

Genetic variation was reviewed in 106 species of marine teleosts. Two heterozygosity estimates were used, one including all protein and enzyme loci and a second excluding the non-enzymatic protein loci. Mean heterozygosities are 0.055±0.036 based on all loci in 106 species and 0.060+0.038 based on enzymatic loci in 89 species. A significant negative correlation was noted between heterozygosity and the proportion of general protein loci included in the estimate. A comparison was made of heterozygosities among taxonomic orders and families, life zones, reproductive mode, geographical range and size. High levels of genetic variation are found in Clupeiformes, Atheriniformes, Pleuronectiformes, temperate pelagic, tropical, intertidal-sublittoral and wide-range species. Low levels of genetic variation are found in Gadiformes, Scorpaeniformes, temperate demersal, polar, and narrowrange species. The most striking differences in heterozygosities are between temperate demersal flatfishes and temperate demersal round fishes. It is suggested that much of the data can be explained by a habitat specialist-generalist model, with high heterozygosities in specialists and low heterozygosities in generalists, but that this is only one of a mosaic of factors which influence genetic variation.

Fine structure of the scales of Fundulus heteroclitus was examined by scanning and transmission electron microscopy. The concentric ridges of the scale surface were characterized by the presence of minute, highly calcified, denticles or tooth-like processes. Needle-shaped crystals of hydrox-yapatite were precipitated not only in the osseous layer but in the intimate lamellae of the fibrillary plate except in portions just below the grooves. The calcification of the osseous layer was observed to proceed by filling the matrix with patches of crystals. The fibrillary plate appeared to calcify by invasion of crystals from the upper calcified zone into spaces between collagen fibers.

Ten species of teleosts belonging to three families of Atheriniformes (Poeciliidae, Cyprinodontidae, Goodeidae) have been tested for their ability to survive in fresh water without a pituitary gland. The fish of the current report respond similarly to Atheriniformes previously investigated. Hypophysectomized fish enter into osmotic shock and generally die within three weeks when placed into fresh water but they will survive in dilute sea water (1.2% solution of commercial sea salts). Fish belonging to Poecilia survive for the shortest period. By comparison the mean survival time for Xiphophorus is longer and more variable. No correlation exists between the number of days hypophysectomized fish are held in one third sea water prior to testing and the length of time they survive in fresh water. This is also true for fish challenged a second time after recovering from osmotic shock. Presumably, osmotic difficulty commences upon exposure to fresh water but can be alleviated when fish are returned to dilute sea water. Five hypophysectomized fish survived in fresh water. Each of these exceptional animals had suffered brain damage during surgery. The significance of these observations is discussed as it is related to the natural habitat and salt tolerances of the fish studied.

Two clones of the hermaphroditic fish Rivulus marmoratus Poey, identified by their intraclonal histocompatibilities and interclonal histoincompatibility, were kept through successive uniparental generations, each fish in isolation. These hermaphrodites emit internally self-fertilized eggs incubated up to 2 1/2 days intraparentally and thereafter extraparentally. By extraparental incubation at low temperature, primary males can be produced at will from eggs otherwise yielding hermaphrodites. Secondary males originate from hermaphrodites, usually late in life, if the ovarian component of the ovotestis involutes. There are no females. Eggs from an aberrant hermaphrodite chronically emitting un-self-fertilized eggs were cross-fertilized artificially and also naturally by sperm from a primary male. A fin graft from the clone of the male parent was accepted (autograft reaction) by the interclonal hybrid, showing that amphimixis had occurred and that the clone of the graft donor is homozygous for the histocompat...

The Atheriniformes is an order of teleost fish which consists of the Atherinoidei (sand smelts etc.), Cyprinodontoidei (tooth-carps) and Exocoetoidei (halfbeaks etc.). Some of its members have protrusible upper jaws and some do not. Photographs have been taken of two species of Cyprinodontoidei feeding, to discover how they use their jaws, which are protrusible. The anatomy and mechanisms of the jaws of these and of various other Atheriniformes have been studied. The terminology of the kinematics of machines is used in a general discussion of the mechanisms of teleost jaws. Anatomical similarities between the jaws of Acanthopterygii, Cyprinoidei and Atheriniformes are noted and discussed.

Atherinella blackburni is a silverside species whose occurrence on the Brazilian coast was not properly registered until recently. So far, records of its distribution along the Brazilian shore were limited to Itaparica Island, Bahia State, and Porto Inhaúma, Rio de Janeiro State. In a recent survey of the ichthyofauna of Itamambuca Beach, Ubatuba, São Paulo State, 100 specimens of this species were collected, yielding a considerable source of information regarding its ecology and a new southern limit of its distribution. A detailed survey of an ichthyological collection revealed lots of this species from regions of the Brazilian Northeast, resulting in a northward expansion of the occurrence of A. blackburni in Brazilian waters. Besides the populations found on the Brazilian coast, the species also occurs discontinuously in the Atlantic coasts of Costa Rica, Panama and Venezuela. Meristic and morphometric analysis showed overlapped values between Brazilian populations and the ones closer to the Caribbean. An ecological study of A. blackburni at Itamambuca Beach revealed that it is a predominantly diurnal species with preference for warm and salty waters, often occurring in sandy-bottom environments. It was more abundant in Summer and Winter, when individuals with smaller values of length and weight also occurred.

The coupling between clonal modes of reproduction and hybridization in unisexual vertebrates has led to the hypothesis that heterosis accounts for their ecological success (the "spontaneous heterosis" hypothesis). High levels of genic heterozygosity characteristic of unisexual-hybrid vertebrates are believed to result in enhanced growth, survivorship, and fertility relative to their sexual ancestors. To test this hypothesis, we synthesized 33 new unisexual-hybrid strains of fishes in the genus Poeciliopsis (Atheriniformes: Poeciliidae). On average, the synthetic unisexuals had lower survivorship and a higher incidence of birth defects than either of the sexual ancestors or two natural strains of unisexuals. However, a subset of these synthetic unisexuals exhibited characteristics within the range of the sexual ancestors and natural unisexual strains. These results support the alternative hypothesis that the ecological success of natural unisexuals results from selection of the most fit clones from a broad spectrum of genotypes that arose via multiple hybrid events. We propose that the coupling between unisexuality and hybridization in the vertebrates exists because hybridization is a dysgenic process that can disrupt normal gametogenesis and thus lead to clonal reproduction.

Fishes of the genus Xiphophorus (Poeciliidae, Atheriniformes) are found on the Atlantic slope of Mexico and adjacent parts of Central America.

The current status of knowledge and theory pertinent to sex determination and differentiation in teleost fishes was reviewed in advance (Harrington, 1974). The review is critical and selective but based on an inclusive examination of contingent, derivative, and source literature. It provides a cogent introduction to this study, which is a search at the morphogenetic level for the earliest visible manifestations of the differentiation of ovotestes versus primary testes in fish of the same genotype. The present report begins with a retrospective summary of intersexuality in Rivulus marmoratus Poey and of the evidence for the genetic uniformity of our material and its consequences. The new information appropriate to the title of this paper has its context in findings published during the last 14 years by the writer and his co-authors.

Testicular structure in Salmoniformes, Perciformes, Cypriniformes, and Atheriniformes has been examined and reinterpreted on the basis of two different tubular types, distinguished from each other by the intratubular distribution of spermatogonia. In the salmoniform, perciform, and cypriniform teleosts studied, spermatogonia are distributed along the entire length of the testicular tubules. However, in the atheriniform teleosts spermatogonia are restricted to the distal end of the tubule. Sperm development in teleosts is cystic, cysts being comprised of Sertoli-cell processes. In both testicular types described, Sertoli cells phagocytize spermatid residual bodies. Together witb the germ cells, they comprise the only intratubular cell types within the teleostean testis. Boundary cells are located immediately outside of the tubule basement membrane. They do not form a complete layer over the tubule surface; therefore, interstitial Leydig cells and blood vessels may border directly upon the tubular basement membrane.

The development of the olfactory organ in the rainbow fish, Nematocentris maccullochi, was studied using scanning and transmission electron microscopy; it was compared with the developmental process in other teleosts, especially in the closely related atherinids and cyprinodonts. The formation of the nares parallels that in atherinids, salmonids, cyprinids and heterosomats, but differs from that found in cyprinodonts. Another ontogenetic feature in which the olfactory organs of the rainbow fish and also of atherinids differ from those of cyprinodonts, is the occurrence of transitory kinociliary cells which disappear during the postlarval period. The divergent evolutionary pathways are discussed with reference to experimental investigations. During development, ciliated and microvillous receptor cell types occur. At the primary larval stage ciliated receptor neurons are exclusively present. At a later stage the microvillous type develops and becomes equal in frequency. Thus, the microvillous receptor represents a separate type of olfactory neuron and is not a progenitor of the ciliated receptor cell.

Atherina hepsetus [spec. nov.] Atherina. @/D. 8, 12. P. 13. V. 1/6. A. 16. C. 17. Arted. syn. 117. Atherina. Gron. mus. 1. n. 66. Atherina. @/D. 6, 12. P. 13. V. 6. A. 10. C. - - Hasselqv. iter. 382. Atherina Hepsetus. @/D. 8, 9. P. 12. V. 6. A. {1/13}. C. 20. Habitat in Mari Mediterraneo., Published as part of Linnaeus, Carolus, 1758, Systema Naturae per regna tria naturae: secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis, Stockholm :Laurentius Salvius on page 315, DOI: 10.5962/bhl.title.542, http://zenodo.org/record/3922206

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:21:55Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:40:07Z : No. of bitstreams: 1 2-s2.0-34047189358.pdf: 465158 bytes, checksum: d55b9a0306acc7880749ca28f118c7c5 (MD5) Made available in DSpace on 2014-05-27T11:21:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-07-01 This paper describes the karyotype of Odontesthes regia by means of Giemsa staining, C-banding, to reveal the distribution of the constitutive heterochromatin, and by Ag-staining and fluorescent in situ hybridization (FISH), to locate ribosomal genes (rDNA). The chromosome diploid modal count in the species was 2n = 48. The karyotype is composed of one submetacentric pair (pair 1), 16 subtelocentric pairs (pairs 2 to 17), and 7 acrocentric pairs (pairs 18 to 24). With the exception of pair 1 it was not possible to classify the homologous chromosomes accurately because differences in chromosome size were too slight between adjacent pairs. The distribution of C-banded heterochromatin allowed for a more accurate matching of the majority of chromosomes of the subtelocentric series. Silver staining of metaphase spreads allowed for the identification of Nucleolus Organizer Regions (Ag-NOR) on pair 1. FISH experiments showed that 18S rDNA sequences were located, as expected, in the same chromosome pair identified as the Ag-NOR-bearing one. Departamento de Ciencias del Mar Universidad Arturo Prat, Casilla No 121, Iquique Escuela de Ciencias Aplicadas del Mar Universidad de Oriente, Apartado Postal 147, Isla de Margarita Instituto Oceanográfico de Venezuela Universidad de Oriente, Cumaná Departamento de Morfologia Instituto de Biociências Universidade Estadual Paulista, 18618-000 Botucatu, Sõ Paulo Departamento de Morfologia Instituto de Biociências Universidade Estadual Paulista, 18618-000 Botucatu, Sõ Paulo

The GH (growth hormone) cDNA sequence of the marine silverside fish Odontesthes argentinensis was obtained using the RACE protocol (Rapid Amplification of cDNA Ends). The marine silverside GH cDNA sequence is 928 nucleotides long and was found to encode a polypeptide of 204 amino acids, including a signal peptide of 17 amino acids. The 5' and 3' untranslated regions of the messenger are 109 and 204 nucleotides long, respectively. The deduced GH amino acid sequence was used to infer a phylogenetic tree with GH amino acid sequences from representative species belonging to the Euteleostei Subdivision using the maximum parsimony method. The topology found is according to the major phylogenetic grouping of euteleosts. The results corroborate the hypothesis that atherinids are not related to paracanthopterygians as previously suggested, and show a lack of solid synapomorphies among most of the Acanthopterygii Orders analysed indicating a complex assemblage of fishes in which the phylogenetic tree remains indeterminable.

FITZSIMONS, J. M. 1970. Comparative behavior and systematics of two genera of goodeid fishes (Atheriniformes, Cyprinodontoidei) from the Mexican Plateau. Unpubl. Ph.D. Thesis, Univ. of Michigan, Ann Arbor. 1972. A revision of two genera of goodeid fishes (Cyprinodontiformes, Osteichthyes) from the Mexican Plateau. Copeia 1972:728-756. HUBBS, C. L., AND C. L. TURNER. 1939. Studies of the fishes of the order Cyprinodontes. XVI. A revision of the Goodeidae. Misc. Publ. Mus. Zool. Univ. Mich. 42. MILLER, R. R. 1948. The cyprinodont fishes of the Death Valley system of eastern California and southwestern Nevada. Ibid. 68. , AND J. M. FITZSIMONS. 1971. Ameca splendens, a new genus and species of goodeid fish from western Mexico, with remarks on the classification of the Goodeidae. Copeia 1971:1-13.

Electrophoretic and morphological comparisons were made between 14 populations representing the major part of the known range of the nominal fish species, Pseudomugil signifer Kner and Pseudomugil signatus (Gunther), described from the fresh and brackish waters of eastern Australia. Analysis by principal components was used to assess the morphological data. .Clinal variation revealed in 10 morphological characters and at two enzyme loci was found to bridge most of the previously described differences between species. The type material of P. signatus afinis from the Low Isles, Queensland, was re-examined and did not appear to differ morphologically from the coastal species. It is therefore suggested that the populations studied represent a single species Pseudomugil signifer Kner.

The genus Pseudomugil is revised and compared with its nominal sister groups. Popondichthys and Kiunga. which were previously placed within the family Melanotaeniidae . Pseudomugil, as a result of this study. is considered to belong to a distinct Old World atherinoid family. Pseudomugilidae. having two subfamilies. Pseudomugilinae and Kiunginae. with 13 species included in the first and 1 in the second . A key for and a full description of all the presently known species and their phenetic relationships are presented . P. helodes is no longer recognized as a member of the family Pseudo- mugilidae and is placed into the family of sailfin silversides, Telmatherinidae .

A new silverside (Atheriniformes: Atherinidae) of the previously monotypic genus Colpichthys is described from the Gulf of California, Mexico. Both species occupy near-shore habitats in the northern part of the Gulf of California, with the new species, Colpichthys hubbsi, restricted to the Colorado River delta region. The range of the sister species, C. regis (Jenkins and Evermann), overlaps marginally in the southern reaches of the delta. The new species is most abundant in the mouth of the Colorado River, although several collections have been taken from lagoons to the south. Features that distinguish the new species from C. regis include a more posterior placement of the dorsal fins, large scales, a small head, lack of a posterior extension of the gas bladder beyond the gut cavity, and lack of modified anterior caudal vertebrae characteristic of the other members of this subfamily. The significance of sister species in the same geographical region and the phylogenetic and biogeographic affinities of these Gulf of California species is discussed.