scholarly journals A tagging method for very small fish

2018 ◽  
Author(s):  
Tessa K. Solomon-Lane ◽  
Hans A. Hofmann
Keyword(s):  
Early Life ◽  
Cichlid Fish ◽  
Model System ◽  
Small Fish ◽  
Life History Stages ◽  
Unique Color ◽  
Passive Integrated Transponders ◽  
Astatotilapia Burtoni ◽  
Tagging Methods ◽  
Over Time

ABSTRACTThe ability to reliably identify individuals over time and across contexts is essential in numerous areas of science. There are a variety of well-established methods for uniquely marking individuals, such as using paint or dye, visible implant elastomer tags, numbers or barcodes glued to the animal, passive integrated transponders, and more. For some species, life history stages, and/or experiments, however, these existing tagging methods are not sufficient. Here, we describe the method we developed for tagging juveniles of the African cichlid fish, Astatotilapia burtoni, which are too small for the methods used to tag adults. We used fishing line threaded through the needle of an insulin syringe to tie a loop of line through the dorsal muscle of juveniles as small as 10 mm standard length. Unique color patterns on the line can be used to distinguish among individuals. The tag is compatible with normal locomotion and social behavior, discernible to the eye and on camera, durable enough to last at least months, and the juvenile can grow with the tag. For A. burtoni, which is a model system in social neuroscience, the lack of an appropriate tagging method for very small juveniles likely contributes to the relative lack of early-life studies, and the same may be true for other small species. We expect this method to be useful in a variety of species and will facilitate the integration of organismal and behavioral development into more research programs.

scholarly journals Developmental plasticity of the stress response in female but not in male guppies

2018 ◽  
Vol 5 (3) ◽  
pp. 172268 ◽  
Author(s):  
L. Chouinard-Thuly ◽  
A. R. Reddon ◽  
I. Leris ◽  
R. L. Earley ◽  
S. M. Reader
Keyword(s):  
Life History ◽  
Stress Response ◽  
Stress Responses ◽  
Early Life ◽  
Developmental Plasticity ◽  
Life Experiences ◽  
Population Variation ◽  
Small Fish ◽  
Cortisol Release ◽  
Over Time

To survive, animals must respond appropriately to stress. Stress responses are costly, so early-life experiences with potential stressors could adaptively tailor adult stress responses to local conditions. However, how multiple stressors influence the development of the stress response remains unclear, as is the role of sex. Trinidadian guppies ( Poecilia reticulata ) are small fish with extensive life-history differences between the sexes and population variation in predation pressure and social density. We investigated how sex and early-life experience influence hormonal stress responses by manipulating conspecific density and perceived predation risk during development. In adults, we sampled cortisol twice to measure initial release and change over time in response to a recurring stressor. The sexes differed considerably in their physiological stress response. Males released more cortisol for their body mass than females and did not reduce cortisol release over time. By contrast, all females, except those reared at high density together with predation cues, reduced cortisol release over time. Cortisol responses of males were thus less dynamic in response to current circumstances and early-life experiences than females, consistent with life-history differences between the sexes. Our study underscores the importance of early-life experiences, interacting ecological factors and sex differences in the organization of the stress response.

Significance of Egg and Larval Size to Recruitment Variability of Temperate Marine Fish

1991 ◽  
Vol 48 (10) ◽  
pp. 1820-1828 ◽  
Author(s):  
Pierre Pepin ◽  
Ransom A. Myers
Keyword(s):  
Life History ◽  
Marine Fish ◽  
Early Life ◽  
Univariate Analysis ◽  
Early Life History ◽  
Fish Populations ◽  
Larval Size ◽  
Larval Phase ◽  
Life History Stages ◽  
Recruitment Variability

Recruitment variability is commonly associated with fluctuations in abundance of marine fish populations. Previous studies have focussed on stock-specific correlative or mechanistic models or on comparisons of recruitment variations of several stocks or species. The purpose of this study is to determine whether recruitment variability of commercial marine fish populations is associated with either size or the duration of early life history stages. The analysis was performed with data from 86 stocks representing 21 species of commercial marine fish. Univariate analysis shows that neither egg size nor the length at hatch is significantly correlated with recruitment variability. The change in length during the larval phase, which is representative of the duration of the stage, is significantly positively correlated with recruitment variability. Multivariate analysis shows that recruitment variability increases with increasing length at metamorphosis but that recruitment variability is poorly associated with length at hatch. The degree of serial correlation is related to the relative duration of egg and larval stages. The results clearly indicate that recruitment variability is linked to characteristics of early life history stages.

Juveniles and larvae of eleven fish species collected from three countries of the Arabian Gulf and the Arabian Sea

2021 ◽  
Vol 325 (4) ◽  
pp. 457-468
Author(s):  
L.A. Jawad ◽  
F. Mutlak ◽  
A.R.M. Mohamed ◽  
J.M. Al-Mamry ◽  
E.K. Hameed ◽  
...  
Keyword(s):  
Early Life ◽  
Arabian Sea ◽  
Arabian Gulf ◽  
Early Life History ◽  
Freshwater Environment ◽  
Life History Stages ◽  
Tenualosa Ilisha ◽  
Sparidentex Hasta ◽  
Available Information ◽  
First Time

The finding of larval and juvenile specimens from the Omani coast of the Arabian Sea and the Arabian Gulf waters of Saudi Arabia and Iraq is reported for the first time. Based on available information, one larva was a leptocephalus, Conger sp. (family Congridae) and one larva of an acronurus stage belonging to the genus Acanthurus (family Acanthuridae). Also juveniles of the following families are included in the present study: Clupeidae – Tenualosa ilisha (Hamilton, 1822) and Nematalosa sp.; Dactylopteridae – Dactyloptena orientalis (Cuvier, 1829); Gobiidae – Acentrogobius sp.; Bothidae – Arnoglossus aspilos (Bleeker, 1851); Scatophagidae – Scatophagus argus (Linnaeus, 1766); Sparidae – Acanthopagrus arabicus Iwatsuki, 2013 and Sparidentex hasta (Valenciennes, 1830); Tetraodontidae – Lagocephalus sp. The discovery of the barred rather than spotted juveniles of S. argus collected from pure freshwater environment of the Shatt al-Arab River, Basrah, Iraq was remarkable; it raises questions whether there is more than one species within the nominal S. argus. For both larvae and juveniles of bothid flounders, the olfactory organ is a useful character for the examination of the developmental stage of the metamorphosing specimens. The occurrence of the different early life history stages of fishes from the three Arabian countries shows the needs them to be studied further so that inferences about the areas and periods of spawning and development of these fishes can be made more accurately.

The Ecology of Juvenile Salmon in the Northeast Pacific Ocean: Regional Comparisons

2007 ◽  
Keyword(s):  
Coastal Waters ◽  
Pacific Salmon ◽  
Size Class ◽  
Small Fish ◽  
Lepeophtheirus Salmonis ◽  
Northeast Pacific ◽  
Salmon Lice ◽  
Regional Comparisons ◽  
Northeast Pacific Ocean ◽  
Over Time

Abstract.—We report patterns of infestation with motile salmon lice, <em>Lepeophtheirus salmonis</em>, on Pacific salmon collected with a surface trawl in coastal waters of Oregon, Washington, British Columbia, and Alaska during 2002 and 2003. Salmon lice were observed on all salmon species examined and in all areas surveyed. The prevalence and abundance of lice infestation varied significantly among species, size-classes, seasons, regions, and years, with larger salmon being consistently more heavily infested than small salmon. The number of lice infesting the small size-class (100–400 mm) of salmon rarely exceeded 5 lice per fish with a mean abundance generally below 0.2 lice per fish. Lice prevalence and, to a lesser extent, lice abundance increased over time in small fish, with lower values during spring and higher values in the following winter, and continued to increase in larger and older fish. There were no apparent effects of water temperature on lice infestation in Pacific salmon. This study suggested that salmon infested with lice remained in coastal waters throughout the year. We suggest that lice on salmon that overwinter in coastal waters will contribute to a pool of infective copepodids in these habitats.

scholarly journals Short-term exposure of Chinook salmon (Oncoryhnchus tshawytscha) to o,p-DDE or DMSO during early life-history stages causes long-term humoral immunosuppression.

2003 ◽  
Vol 111 (13) ◽  
pp. 1601-1607 ◽  
Author(s):  
Ruth H Milston ◽  
Martin S Fitzpatrick ◽  
Anthony T Vella ◽  
Shaun Clements ◽  
Deke Gundersen ◽  
...  
Keyword(s):  
Life History ◽  
Chinook Salmon ◽  
Early Life ◽  
Early Life History ◽  
Short Term ◽  
Life History Stages ◽  
Short Term Exposure
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