Search results for "Actinopterygii"
showing 10 items of 210 documents
Effects of repeated handling, with or without anaesthesia, on feed intake and growth in juvenile rainbow trout, Oncorhynchus mykiss (Walbaum)
2006
The effects of weekly anaesthetization with clove oil and tricaine methanesulphonate (MS-222) on feed intake and growth were examined in juvenile rainbow trout, Oncorhynchus mykiss (Walbaum), held individually. Repeated handling without anaesthetics significantly reduced feed intake and weight gain compared with an unhandled control group during an 8-week experiment. When anaesthetics were used during handling the feed consumption and weight gain were significantly (MS-222) or not significantly (clove oil) higher than in fish handled without anaesthesia. When compared with the unhandled control group, neither of these two anaesthetics had significant effects on feed intake but, in contrast …
Säugetiere, Fisch-Otolithen, Ostracoden, Mollusken und Charophyten aus den Süßwasser- Schichten (Oligozän) von Wolfsheim im Mainzer Becken
2000
The Suswasser-Schichten (Freshwater Beds) (Oligocene) in the Mainz Basin are a paleontologically poorly studied formation. A succession of predominantly lacustrine marls from Wolfsheim can be attributed to the Suswasser-Schichten on basis of a palaeoecological and biostratigraphic analysis of its mammal teeth, fish otoliths, ostracods, mollusks, foraminifera and charophytes. The occurrence of the mammal speciesToeniodus aff.hexalophodus andIssiodoromys minor (primitive form) enables an attribution of the Suswasser-Schichten to the reference level MP 24 of the eurasiatic mammal biostratigraphic zonation. As the reference fauna of level MP 24 is believed to occur in a lithostratigraphically m…
Lethal toxicity of Lindane on a teleost fish,Anguilla anguillafrom albufera lake (Spain): Hardness and temperature effects
1988
This paper reports the results of toxicity tests conducted using Anguilla anguilla under three different water temperature (15, 22 and 29 degrees C) and two hardness regimes (250 and greater than 600 ppm CaCO3). The 96-h LC50 increased in the experimental medium (p less than 0.05) by an order of magnitude from 0.32 to 0.45 mg/L between 15 and 29 degrees C. However in the natural medium it is similar (p greater than 0.05) (0.54 to 0.55 mg/L) for these same temperatures. The toxicity of Lindane on eels increased when the water hardness decreased. The 24, 48, 72 and 96-h LC50 for this fish in both media is less at 15 degrees C (96-h LC50 = 0.32 and 0.55 mg/L) than at 29 degrees C (96-h LC50 = …
FISH mapping of 18S-28S and 5S ribosomal DNA, (GATA)n and (TTAGGG)n telomeric repeats in the periwinkle Melarhaphe neritoides (Prosobranchia, Gastrop…
2001
Spermatocyte chromosomes of Melarhaphe neritoides (Mollusca, Prosobranchia, Caenogastropoda) were studied using fluorescent in situ hybridization (FISH) with four repetitive DNA probes (18S rDNA, 5S rDNA, (TTAGGG)n and (GATA)n). Single-colour FISH consistently mapped one chromosome pair per spread using either 18S or 5S rDNA as probes. The telomeric sequence (TTAGGG)n hybridized with termini of all chromosomes whereas the (GATA)n probe did not label any areas. Simultaneous 18S-5S rDNA and 18S-(TTAGGG)n FISH demonstrated that repeated units of the three multicopy families are closely associated on the same chromosome pair.
Conserved synteny of mammalian imprinted genes in chicken, frog, and fish genomes
2006
Conservation of synteny of mammalian imprinted genes between chicken and human suggested that highly conserved gene clusters were selected long before these genes were recruited for genomic imprinting in mammals. Here we have applied in silico mapping of orthologous genes in pipid frog, zebrafish, spotted green and Japanese pufferfish to show considerable conservation of synteny in lower vertebrates. More than 400 million years ago in a common ancestor of teleost fish and tetrapods, ‘preimprinted’ chromosome regions homologous to human 6q25, 7q21, 7q32, 11p15, and 15q11→q12 already contained most present-day mammalian imprinted genes. Interestingly, some imprinted gene orthologues which are…
Evaluating fish assemblages associated with gas platforms: Evidence from a visual census technique and experimental fishing surveys
2010
Fish assemblages associated with extractive platforms were surveyed, for the first time, using traditional fishing surveys (bottom gill net) and an underwater visual census (UVC) technique in order to test the effectiveness and to identify strengths and weaknesses of both methods. The study was carried out during three seasons at two offshore gas platforms (Eleonora and Squalo C) located in the central Adriatic Sea. Both methods recorded a similar number of fish species although with only eight species in common, thus supplying complementary information and a good estimate of the total fish species richness (39) associated with these gas platforms. The use of innovative techniques, such as …
Contaminants of emerging concern in freshwater fish from four Spanish Rivers.
2019
This study investigated the occurrence of 135 contaminants of emerging concern (CECs) – pharmaceuticals, pesticides, a set of endocrine disrupting compounds (EDCs) (parabens, bisphenols, hormones, triazoles, organophosphorus flame retardants and triclosan), UV-filters, perfluoroalkyl substances (PFASs) and halogenated flame retardants (HFRs) – in 59 fish samples, collected in 2010 in 4 Spanish Rivers (Guadalquivir, Júcar, Ebro and Llobregat). Of the 135 CECs, 76 including 8 pharmaceuticals, 25 pesticides, 10 EDCs, 5 UV-filters, 15 PFASs and 13 HFRs were detected. Pharmaceuticals were the less frequently found and at lower concentrations. Pesticides, EDCs, UV-filters, PFASs and HFRs were det…
Morphological and attachment changes of Lamellodiscus theroni (Monogenea: Diplectanidae) during its post-larval development on fish.
2014
Species of the genus Lamellodiscus Johnston et Tiegs, 1922 (Monogenea: Diplectanidae) are characterised by a complex haptor bearing many different attachment elements: two pairs of main hooks joined by medial bars, 14 peripheral marginal hooks and one or two lamellodiscs, formed by several overlapping sclerotised plates (lamellae). These haptoral structures appear gradually during parasite development and, therefore, attachment strategies vary with developmental stage. The main aim of this work was to study the developmental changes of Lamellodiscus theroni Amine, Euzet et Kechemir-Issad, 2007 under experimental conditions, with special attention to the gradual variations in attachment stra…
Thiobencarb-Induced Changes in Acetylcholinesterase Activity of the Fish Anguilla anguilla
2002
Abstract European eels (Anguilla anguilla) were exposed to sublethal thiobencarb concentrations in a continuous flow-through system for 4 days. Brain, muscle, and gill acetylcholinesterase (AChE) activities were evaluated after 2, 12, 24, 48, 72, and 96 h herbicide exposure. Thiobencarb induced significant inhibitory effects on the total and specific AChE activity of A. anguilla, ranging from >30–40% inhibition in eel brain and gills to >50% inhibition in muscle tissue 2 h after the initial exposure. In a second experiment, eels were exposed to thiobencarb for 96 h and then allowed a period of recovery in pesticide-free water. Following 1 week of recovery, the AChE activity of affected eels…
Paradiplozoon iraqensis n. sp. (Monogenea: Diplozoinae) from Cyprinion macrostomum (Cyprinidae) in the Tigris River, Iraq
2015
A new species of monogenean diplozoid, Paradiplozoon iraqensis n. sp., from the gills of Cyprinion macrostomum Heckel from the Tigris River in Tikrit, Iraq is described. P. iraqensis n. sp. is distinguished from other species of the genus by the size of plicae on the fore- and hind body, the number of the branches of the intestinal caecum in fore body, intestinal caecum not extending to haptor, the size of the clamps and the morphology of the clamp sclerites, and by the length of the central hooks. Details of the shape and size of eggs, and of the reproductive system and prohaptoral region are provided. The present study raises the number of species of Paradiplozoon recorded in Iraq to 15.