In this study, gonadogenesis, the effect of temperature (15, 20 and 25°C) on sex differentiation, and annual changes in the gonads of mature lake minnow Eupallasella percnurus (Pallas, 1814) were determined. The lake minnow was found to be a primary gonochoristic fish species, where gonads are formed directly in the ovaries or testes. The morphological differentiation of gonads was initiated 35days post hatch (DPH) when two types of gonadal anlages were visible: a pear-shaped gonad attached by a single mesentery string and a spindle-shaped gonad attached on both sides to the peritoneum. Gonadogenesis occurred faster in females than in males, with the first previtellogenic oocytes and ovarian lamellae being already observed in 45 DPH fish. In males, cytological differentiation occurred approximately 85 DPH, when the fish reached an average body weight of more than 400mg. No significant effect of rearing temperature on sex ratio in lake minnow juveniles was observed. The proportion of males and females was similar (close to 1:1) in all of the thermal-treated groups, although there were effects of temperature on the final sizes of fish. Histological examination of wild, mature lake minnow ovaries during the annual cycle (from May to February the following year) showed asynchronous oocyte maturation. The testes were characteristic of multi-batch spawning fish. Quantitative dominance of spermatids and mature spermatozoa in May was observed, while the presence of primary and secondary spermatocytes in all other periods was confirmed. These changes were also reflected in the seasonal variation in the gonado-somatic index in both sexes, with the highest mean values of 11.2% (females) and 4.0% (males) in May, which were found to be significantly different to all other periods. The data presented in this study provide an important contribution to our understanding of the biology and reproductive strategy of the endangered lake minnow.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.anireprosci.2016.11.006 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Rice Straw-Derived Biochar Mitigates Microcystin-LR-Induced Hepatic Histopathological Injury and Oxidative Damage in Male Zebrafish via the Nrf2 Signaling Pathway.
Toxins (Basel)
December 2024
College of Life and Environmental Sciences, Hunan University of Arts and Science, Changde 415000, China.
Microcystin-leucine arginine (MC-LR) poses a serious threat to aquatic animals during cyanobacterial blooms. Recently, biochar (BC), derived from rice straw, has emerged as a potent adsorbent for eliminating hazardous contaminants from water. To assess the joint hepatotoxic effects of environmentally relevant concentrations of MC-LR and BC on fish, male adult zebrafish () were sub-chronically co-exposed to varying concentrations of MC-LR (0, 1, 5, and 25 μg/L) and BC (0 and 100 μg/L) in a fully factorial experiment.
View Article and Find Full Text PDFWater quality and stock assessment of Schizothorax niger (Alghad snowtrout) in Manasbal Lake, Kashmir Himalaya.
Environ Monit Assess
December 2024
Fish Biology and Limnology Research Laboratory, Department of Zoology, University of Kashmir, Srinagar-190006, Jammu and Kashmir, India.
The current work was conducted to investigate fisheries dynamics, rate of growth, and mortality, along with demographic features of Schizothorax niger using length-frequency data collected monthly from Manasbal Lake from August 2020 and July 2022. The length data for estimation was categorized into 13 bins, and population parameters were explored utilizing various options in ELEFAN I, with the best fit (Rn = 0.282) calculated by means of the FiSAT-II application.
View Article and Find Full Text PDFArticle Synopsis
- - A new species of small fish called Enteromius gamo sp. nov. has been identified in rivers and wetlands near lakes Abaya and Chamo in south-western Ethiopia.
- - This species is part of a group typically recognized as E. kerstenii and has unique features such as a thick last unbranched ray in the dorsal fin, fewer scales on its body, and distinctive color markings on its operculum.
- - Genetic analysis shows significant differences from E. kerstenii found in Tanzania, and the new species can also be identified by shorter barbels compared to other related species in East Africa.
Receptor tyrosine kinase inhibition leads to regression of acral melanoma by targeting the tumor microenvironment.
J Exp Clin Cancer Res
December 2024
The Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA.
Background: Acral melanoma (AM) is an aggressive melanoma variant that arises from palmar, plantar, and nail unit melanocytes. Compared to non-acral cutaneous melanoma (CM), AM is biologically distinct, has an equal incidence across genetic ancestries, typically presents in advanced stage disease, is less responsive to therapy, and has an overall worse prognosis.
Methods: An independent analysis of published sequencing data was performed to evaluate the frequency of receptor tyrosine kinase (RTK) ligands and adapter protein gene variants and expression.
Bloom-forming planktonic Microcystis and benthic Oscillatoria-induced oxidative stress and inflammatory responses in juvenile silver carp and bighead carp.
Toxicon
January 2025
Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China.
As global warming and water eutrophication, the multiple proliferation of harmful cyanobacteria can form algal blooms and cause serious ecological problems. In recent years, the large-scale and persistent cyanobacterial blooms occur frequently worldwide and have attracted widespread attention due to the harmful impacts. Among these harmful bloom-forming cyanobacteria, the ecological and toxicological impacts of planktonic cyanobacteria have been extensively studied.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!