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At least 199 records · Page 11Linked to original sources
PubMed1983

The aminergic system in the brain of Blennius incognitus (Bath 1968) (Teleostei, Perciformes).

In the brain of Blennius incognitus the distribution of biogenic amines was investigated by means of formaldehyde-induced fluorescence (FIF). The telencephalon of Blennius is devoid of fluorescent perikarya. Fluorescent telencephalic fibers and terminals contain either dopamine (DA), noradrenaline (NA), or an indolamine. Two diencephalic nuclei display fluorescent perikarya, the nucleus recessus lateralis and the nucleus recessus posterioris; both nuclear regions contain DA. Only occasionally single green-fluorescent perikarya are found within the ependymal lining of the caudal portion of the recessus lateralis. Four fluorescent nuclei, two catecholamine-containing nuclei and one indolamine-containing nucleus, are present in the tegmentum of the midbrain and in the medulla oblongata. Three of these nuclei, N1 and N3, consist of large, green-fluorescent neurons, which apparently contain NA. N2, located medial to the nucleus isthmi, is formed by several clusters of small neurons, which show a yellow indolamine fluorescence. Caudal to the calamus scriptorius another green-fluorescent nucleus (N4) is visible.

Animals↗
PubMed1979

Electron microscopic study of the giant cells in the olfactory bulb of labyrinth fish (Belontiidae, perciformes).

The giant cells in the olfactory bulb of labyrinth fish, most likely belonging to the nervus terminalis, show ultrastructural features of active synthesis of secretory material. Dense core vesicles (70--100 nm in diameter), found in the perikaryon as well as in the axon, are the possible storage sites of the secretory substance. Its chemical nature is unknown. In some of these vesicles acid phosphatase is demonstrable. Large membrane-bound bodies (up to 2000 nm in diameter), either containing an electron dense matrix or debris of cytoplasmic organelles, are also acid phosphatase-positive, suggesting their lysosomal nature. Some other ultrastructural characteristics of these cells are also described.

Acid Phosphatase↗
PubMed1975

The structure and evolution of parvalbumins. I. Amino acid compositional studies of parvalbumins from four perciform species.

1. Parvalbumins were isolated from the white muscle of Cynoscion regalis, Leiostomus xanthurus, and Menticirrhus americanus of the Sciaenidae and Pomatomus saltatrix of the Pomatomidae. 2. Menticirrhus contains three isoparvalbumins. The other species contain two isoparvalbumins which are designated "fast" and "slow" in accord with their electrophoretic mobilities. Measurements of the denatured molecular weights show the "slow" isoparvalbumins have slightly larger apparent molecular weights, but all apparent molecular weights are in the range 10,400-14,000. 3. Amino acid compositional studies indicate that the fast and slow isoparvalbumins in these fish represent two distinct evolutionary lineages which appear to be evolving at different rates.

Amino Acids↗
PubMed2005

Life-history- and ecosystem-driven variation in composition and residence pattern of seabream species (Perciformes: Sparidae) in two Mediterranean coastal lagoons.

Species composition and length-frequency distributions of six sparid fish species were investigated in two central Mediterranean coastal lagoons off the western coast of Italy: Fogliano and Caprolace. In the former, the sparid fauna was dominated by the gilt-head seabream (Sparus aurata), whereas in Caprolace, species composition was more homogeneous across all six species. Size structure varied considerably among species: S. aurata, Diplodus puntazzo and Diplodus vulgaris had a single-cohort structure in both lagoons, whereas in Diplodus annularis and Diplodus sargus at least two cohorts were identified. In Lithognathus mormyrus inter-lagoon variation was detected, with a single-cohort structure in Fogliano and a two-cohort structure in Caprolace. While inter-specific differences can be explained by variation in life-history strategies among species, intra-specific variation in L. mormyrus is likely to be determined by the known differences between the two habitats: Fogliano being a more confined lagoon, and Caprolace more extensively influenced by the sea.

Animals↗
PubMed2004

A molecular phylogeny of the Percidae (Teleostei, Perciformes) based on mitochondrial DNA sequence.

The family Percidae is among the most speciose families of northern hemisphere fishes with > 178 178 North American species and 14 Eurasian species. Previous phylogenetic studies have been hampered by a lack of informative characters, inadequate taxonomic sampling, and conflicting data. We estimated phylogenetic relationships among 54 percid species (9 of 10 genera and all but one subgenus of darters) and four outgroup taxa using mitochondrial DNA data from the 12S rRNA and cytochrome b genes. Four primary evolutionary lineages were consistently recovered: Etheostomatinae (Ammocrypta, Crystallaria, Etheostoma, and Percina), Perca, Luciopercinae (Romanichthys, Sander, and Zingel), and Gymnocephalus. Except Etheostoma and Zingel, all polytypic genera were monophyletic. The Etheostoma subgenus Nothonotus failed to resolve with other members of the genus resulting in a paraphyletic Etheostoma. The subfamily Percinae (Gymnocephalus and Perca) was not recovered in phylogenetic analyses with Gymnocephalus sister to Luciopercinae. Etheostomatinae and Romanichthyini were never resolved as sister groups supporting convergent evolution as the cause of small, benthic, stream-inhabiting percids in North American and Eurasian waters.

Animals↗
PubMed2005

Molecular phylogeny and evidence for an adaptive radiation of geophagine cichlids from South America (Perciformes: Labroidei).

Nucleotide sequences from the mitochondrial ND4 gene and the nuclear RAG2 gene were used to derive the most extensive molecular phylogeny to date for the Neotropical cichlid subfamily Geophaginae. Previous hypotheses of relationships were tested in light of these new data and a synthesis of all existing molecular information was provided. Novel phylogenetic findings included support for : (1) a 'Big Clade' containing the genera Geophagus sensu lato, Gymnogeophagus, Mikrogeophagus, Biotodoma, Crenicara, and Dicrossus; (2) a clade including the genera Satanoperca, Apistogramma, Apistogrammoides, and Taeniacara; and (3) corroboration for Kullander's clade Acarichthyini. ND4 demonstrated saturation effects at the third code position and lineage-specific rate heterogeneity, both of which influenced phylogeny reconstruction when only equal weighted parsimony was employed. Both branch lengths and internal branch tests revealed extremely short basal nodes that add support to the idea that geophagine cichlids have experienced an adaptive radiation sensu Schluter that involved ecomorphological specializations and life history diversification.

Animals↗
PubMed2005

Phylogenetic relationships of the lamprologine cichlid genus Lepidiolamprologus (Teleostei: Perciformes) based on mitochondrial and nuclear sequences, suggesting introgressive hybridization.

Using sequences of the mitochondrial NADH dehydrogenase subunit 2 gene (ND2, 1047bp) and a segment of the non-coding mitochondrial control region, as well as nuclear sequences including two introns from the S7 ribosomal protein and the loci TmoM25, TmoM27, and UME002, we explore the phylogenetic relationships of Lepidiolamprologus, one of seven lamprologine cichlid genera in Lake Tanganyika, East Africa. Analyses consisted of direct optimization using POY, including a parsimony sensitivity analysis, and maximum likelihood and Bayesian inference for comparison. With respect to Lepidiolamprologus, the results based on the mitochondrial dataset were robust to parameter variation in POY. Lepidiolamprologus cunningtoni was resolved in a large clade sister to ossified group lamprologines, among which the remaining Lepidiolamprologus were nested. In addition to L. attenuatus, L. elongatus, L. kendalli, and L. profundicola, Neolamprologus meeli, N. hecqui, N. boulengeri, N. variostigma, and two undescribed species were resolved in a two-pore Lepidiolamprologus clade sister to Lamprologus callipterus and two species of Altolamprologus. Lepidiolamprologus nkambae, in marked conflict with morphological and nuclear DNA evidence, nested outside of the two-pore Lepidiolamprologus clade, suggesting that the mtDNA signal has been convoluted by introgressive hybridization.

Animals↗
PubMed2003

Spermiogenesis and sperm ultrastructure in Cichla intermedia with some considerations about Labroidei spermatozoa (Teleostei, Perciformes, Cichlidae).

Spermiogenesis and spermatozoal structure were studied in Cichla intermedia, a primitive species of Neotropical Cichlids. The analysis shows that spermiogenesis is characterized by chromatin compaction, flagellum development, nuclear rotation, nuclear fossa formation and residual cytoplasm elimination. In the spermatozoa, the head is round, the nucleus contains highly condensed filamentous clusters of chromatin and an acrosome is absent. The nuclear fossa is slightly eccentric and shows a projection that penetrates into the nuclear outline. The proximal centriole is located in the initial segment of the nuclear fossa. The midpiece and the cytoplasmic channel are long. The mitochondria, about 10 in number, are round or slightly elongated, disposed in two layers around the initial segment of the flagellum. The flagellum has a classical 9+2 axoneme and two lateral fins. The data available show that no characteristics of spermiogenesis or spermatozoa are exclusively found in members of the suborder Labroidei. However, three characteristics seem to be exclusively observed in Cichlidae: (1) compact filamentous clusters of chromatin; (2) slightly eccentric nuclear fossa; and, (3) number of mitochondria.

Animals↗
PubMed1994

Cryopreservation of yellowfin seabream (Acanthopagrus latus) spermatozoa (Teleost, Perciformes, Sparidae).

The effects of both osmolality and cation in the initiation of sperm motility were examined in yellowfin seabream, Acanthopagrus latus. Various factors involved in the cryopreservation of yellowfin seabream spermatozoa on motility are discussed. Extender containing only glucose proved to be a suitable medium for freezing yellowfin seabream spermatozoa to -196 degrees C. Glycerol seems to have a direct osmotic effect on yellowfin seabream sperm cells, and it induced sperm motility before freezing and during thawing. However, this exhausted the energy needed for sperm motility for fertilization. Dimethyl sulfoxide (DMSO) proved superior to ethylene glycerol, propylene glycerol, glycerol and methanol as a cryoprotectant. Prolonged equilibration time had a detrimental effect on both prefreezing and post-thawing sperm motility. The estimated optimum freezing rate was in the range of -20 to -154 degrees C/min. More frozen-thawed than fresh spermatozoa are required to achieve comparable fertilization rates.

Journal Article↗
PubMed2000

Scaling effects on hypoxia tolerance in the Amazon fish Astronotus ocellatus (Perciformes: Cichlidae): contribution of tissue enzyme levels.

Astronotus ocellatus is one of the most hypoxia tolerant fish of the Amazon; adult animals can tolerate up to 6 h of anoxia at 28 degrees C. Changes in energy metabolism during growth have been reported in many fish species and may reflect the way organisms deal with environmental constraints. We have analyzed enzyme levels (lactate dehydrogenase, LDH: EC 1.1.1.27; and malate dehydrogenase, MDH: EC 1.1.1.37) in four different tissues (white muscle, heart, liver, and brain) from different-sized animals. Both enzymes correlate with body size, increasing the anaerobic potential positively with growth. To our knowledge, this is the first description of scaling effects on hypoxia tolerance and it is interesting to explore the fact that hypoxia survivorship increases due to combining effects of suppressing metabolic rates and increasing anaerobic power as fish grow.

Animals↗
PubMed2000

Characterization of neuropeptide Y expression in the brain of a perciform fish, the sea bass (Dicentrarchus labrax).

The distribution of neuropeptide Y (NPY) gene expression was mapped in the brain of the sea bass (Dicentrarchus labrax) by in situ hybridization with 35S-UTP labeled cRNA probes. Gene expression was mainly detected within the forebrain, although NPY mRNA transcripts were also localized in the tectum and tegmentum mesencephali and posterior brain. New NPY-expressing nuclei were found in the dorsal and ventral telencephalon, preoptic area, tuberal hypothalamus, synencephalon, tegmentum mesencephali and posterior brain. The profuse NPY gene expression within the main neuroendocrine areas of the teleost fish further supports a physiological role in the control of the pituitary secretion. In addition, NPY gene was expressed within the primary visual, olfactory and gustatory circuits of teleost which, subsequently, project to hypothalamic feeding center in teleost fish. Our results extend the NPY-expressing areas known in teleost species.

Animals↗
PubMed2004

Molecular phylogeny and biogeography of the Malagasy and South Asian cichlids (Teleostei: Perciformes: Cichlidae).

Phylogenetic relationships of the Malagasy and South Asian cichlids are investigated using nucleotide characters from two mitochondrial genes, a 544 bp region of the large ribosomal subunit (16S) and a 649 bp region of cytochrome c oxidase subunit I (COI). This is the first molecular analysis to include a thorough taxonomic sampling of all Malagasy-South Asian genera, and a near complete taxonomic inventory of all valid species. Parsimony analysis of the combined data set (1193 aligned nucleotide positions) results in a single, completely resolved phylogenetic hypothesis. Results of this analysis, and that based on more comprehensive taxonomic sampling across Cichlidae for 16S alone (554 bp for 73 taxa), indicate that the Malagasy cichlids are paraphyletic, whereas the Malagasy and South Asian cichlids comprise a monophyletic group. In both analyses, the African and Neotropical assemblages are monophyletic. The Malagasy-South Asian cichlids are not recovered as plesiomorphic members of the family in either analysis. Two major clades are recovered within the Malagasy-South Asian assemblage and given subfamilial rank, Etroplinae, comprising Paretroplus (Madagascar) and Etroplus (southern India and Sri Lanka), and Ptychochrominae, comprising Ptychochromis, Ptychochromoides, and Oxylapia, all endemic Malagasy genera. Placement of the endemic Malagasy genus Paratilapia is equivocal depending on the gene fragment(s) analyzed. Inter- and intrageneric relationships within Ptychochrominae and Etroplinae are presented and discussed. The hypothesis of relationships for Cichlidae based on nucleotide characters from 16S alone, arguably the most comprehensive and broadly sampled data set across all major geographic assemblages to date, is congruent with prevailing hypotheses regarding the sequence of Gondwanan fragmentation and a vicariance scenario to explain the current distribution of cichlid fishes.

Animals↗
PubMed2000

Major and 5S ribosomal sequences of the largemouth bass Micropterus salmoides (Perciformes, Centrarchidae) are localized in GC-rich regions of the genome.

Major and 5S ribosomal genes have been localized in the chromosomes of Micropterus salmoides. By C-banding, Ag-staining, CMA3-staining and 45S and 5S fluorescence in-situ hybridization (FISH), we demonstrate that the 45S and 5S ribosomal genes are clustered in two different chromosome pairs and both are located in heterochromatic GC-rich regions. PCR amplification and sequencing of the 5S intergenic non-transcribed sequences have allowed us to identify variability essentially due to a trinucleotide tandem repeat (GCT).

Animals↗