The central mudminnow, Umbra limi (Kirtland), a habitat specialist and resource generalist

1985 ◽  
Vol 63 (8) ◽  
pp. 1753-1764 ◽  
Author(s):  
Kathleen A. Martin-Bergmann ◽  
John H. Gee
Keyword(s):  
Activity Patterns ◽  
Gonadal Development ◽  
Life History Strategies ◽  
Habitat Specialist ◽  
Terrestrial Invertebrates ◽  
Aquatic Respiration ◽  
Spawning Time ◽  
Unpredictable Environment ◽  
First Maturity ◽  
Delayed Spawning

The central mudminnow, Umbra limi (Kirtland), successfully inhabits a variable and unpredictable environment in southern Manitoba streams. Umbra accomplishes this by specializing in habitat and generalizing in resources utilized and life history strategies displayed. Mudminnows are restricted to still waters and show a preference for a variety of cover types. They are morphologically, physiologically, and behaviourally specialized for this habitat. Umbra limi inhabits areas subjected to hypoxia and all sizes are able to use both atmospheric and aquatic respiration. Mudminnows are euryphagic carnivores that eat aquatic and terrestrial invertebrates and fish. They feed from a variety of locations (benthic, midwater, and surface) and organisms attached to vegetation are included in the diet. Activity patterns (including feeding) vary daily and seasonally. Differences in rate of growth, age at first maturity, gonadal development, and survival occur between sexes. Individual and population variability is apparent. Spawning time varies and there is evidence for delayed spawning under unfavourable conditions.

Morphology, Physiology, Behavior, and Ecology of Perca fluviatilis L. and P. flavescens Mitchill

1977 ◽  
Vol 34 (10) ◽  
pp. 1504-1514 ◽  
Author(s):  
J. E. Thorpe
Keyword(s):  
Yellow Perch ◽  
Perca Fluviatilis ◽  
Gonadal Development ◽  
Light Responses ◽  
Total Food ◽  
As Species ◽  
Fish Predators ◽  
Spawning Time ◽  
Effects Of Temperature ◽  
First Maturity

A review of literature on Perca fluviatilis and P. flavescens indicated one difference (in the position of the predorsal bone) sufficient to maintain their separateness as species. Otherwise they are overwhelmingly equivalent biologically. Their distributions are limited by the same effects of temperature, current speed, salinity, and dissolved oxygen. They are similar in gonadal development and age at first maturity; in the effects of water temperature and latitude on spawning time, and of environmental fertility on fecundity; in spawning behavior, fecundity, and the course of larval development. Growth capacities are similar and their expression subject to population density and temperature in the same way. Both species are adapted to a diet of small live animals, but will take whatever is available; cannibalism is characteristic, and may begin at the same early feeding stage. The two species show similarities in diurnal periodicity of feeding and in total food consumption. They also have the same pattern of development of light responses, of schooling, of activity and of daily and seasonal migrations. Within the fish community they fulfill the same role as converters of invertebrate foods into a form suitable for consumption by terminal fish predators, especially Stizostedion spp., influencing the population dynamics of their predators in similar ways. Key words: Percidae, morphology, physiology, ecology, Perca, life history, growth, reproduction, yellow perch, Eurasian perch

Aspects of the reproductive cycle and gonadal development of Murray cod, Maccullochella peelii peelii (Mitchell) (Percicthidae), in Lake Charlegrark and adjacent farm ponds, Victoria, Australia

1995 ◽  
Vol 46 (4) ◽  
pp. 723 ◽  
Author(s):  
GJ Gooley ◽  
TA Anderson ◽  
P Appleford
Keyword(s):  
Gonadosomatic Index ◽  
Testicular Tissue ◽  
Gonadal Development ◽  
Testicular Development ◽  
Male Fish ◽  
Farm Ponds ◽  
Macroscopic Classification ◽  
First Maturity ◽  
Murray Cod ◽  
Size At First Maturity

The gonadal development of Murray cod, Maccullochella peelii peelii, in Lake Charlegrark, Victoria, and adjacent farm ponds was evaluated. Gonadosomatic index, macroscopic classification and histological analysis were used to determine the age at first maturity and the gonadal development in this introduced population. There is a marked difference between the sexes in the size at first maturity, with females maturing at approximately 6 years of age and 2000 g in weight and males maturing at 3-4 years and 700 g. Gonadosomatic index data indicate that spawning occurs around November. Ovarian development in this species follows a pattern similar to that in a number of other teleosts. Testes have a lobular structure. Macroscopic evaluation of ovaries provided a good indication of the stage of the development of the gonad. However, the presence of spermatozoa throughout the year in the gonads of mature male fish makes the macroscopic evaluation of testicular development less reliable. Three cod, approximately 1% of the population, contained gonads with both ovarian and testicular tissue.

scholarly journals Reproductive Biology of Marine Catfish, Arius latiscutatus (Günther, 1864) and Arius gigas (Boulenger, 1911) from the Bays of Guinea

2020 ◽  
pp. 1-13
Author(s):  
Pierre Koivogui ◽  
Yao Aristide Konan ◽  
Bakari Coulibaly ◽  
Essetchi Paul Kouamelan ◽  
Tidiani Koné
Keyword(s):  
Reproductive Biology ◽  
Gonadosomatic Index ◽  
Gonadal Development ◽  
Cold Season ◽  
Oocyte Diameter ◽  
Chi Square ◽  
Coastal Fisheries ◽  
Republic Of Guinea ◽  
Macroscopic Observation ◽  
First Maturity

Background and Objectives: Marine catfish are abundant in the bays of Tabounsou and Sangareah in Republic of Guinea, but the knowledge on their biology is still scanty. The reproductive biology of Arius latiscutatus Günther, 1864 and A. gigas Boulenger, 1911 was studied through monthly sampling, from January to December 2016. Methodology: Fish were caught using gill nets in several sampling sites. Five gonadal stages were described, based on macroscopic observation of gonad form, size, weight, color and oocyte diameter. Results: The population was dominated by males (61%) in A. latiscutatus and females (53%) in A. gigas, showing a sex-ratio of 1:1.54 (Chi-square, P < 0.05) and 1:0.88 (P > 0.05), respectively. The length-weight relationship was a positive allometry for A. latiscutatus and A. gigas, and males (35.37 and 35.47 cm, respectively) reached first maturity earlier than females (39.7 and 40.8 cm, respectively). Changes in the gonadosomatic index (GSI) and in stages of gonadal development showed that A. latiscutatus spawned between April and October, while A. gigas spawned in May to November. The peak of condition factor was observed in June (0.68±0.05) and July (0.55±0.04) in females of A. latiscutatus and A. gigas, respectively. Conclusion: Both species, having only one annual breeding season, A. latiscutatus spawns earlier than A. gigas. Coastal fisheries should be restricted in cold season to preserve the ability of broodstock renewal for these species.

scholarly journals Predicting size at first sexual maturity from length/weight relationship: a case study with an Amazonian catfish

2016 ◽  
Vol 14 (4) ◽  
Author(s):  
Tiago Magalhães da Silva Freitas ◽  
◽  
Vitor Hudson da Consolação Almeida ◽  
Luciano Fogaça de Assis Montag ◽  
Nelson Ferreira Fontoura ◽  
...  
Keyword(s):  
Growth Pattern ◽  
Sexual Maturity ◽  
Gonadosomatic Index ◽  
Gonadal Development ◽  
Visual Identification ◽  
Males And Females ◽  
Two Phases ◽  
First Maturity ◽  
Size At First Maturity

ABSTRACT Relationship between length and weight (LWR) is used to describe aspects concerning the life cycle of fish, but does not considers possible changes during the lifetime mainly due to the sexual maturation. Thus, this study aims to identify the size at first maturity of Auchenipterichthys longimanus (Siluriformes: Auchenipteridae) and infer if the reproductive engagement could change growth pattern, concerning the LWR. Estimates of the size at first maturity (L 50 ) were made by visual identification of gonadal development and through the gonadosomatic index (G SI ). L 50 was estimated as 12.5 cm for males and 13.0 cm for females when applied visual identification of gonads development. L 50 estimates increased to 13.05 cm for males and 13.7 cm for females when estimated from G SI values. LWR was adjusted by using a regular power function and through the polyphasic growth model, with proportionality and allometric coefficients changing in a two phases. The results indicate differences in the growth pattern concerning males and females, as well as polyphasic growth. The change in the growth pattern of the polyphasic LWR was estimated at 11.42 cm for males and 12.53 cm for females, suggesting that changes in the growth pattern can sign-out the attainment maturity in this catfish.

scholarly journals LENGTH AT FIRST MATURITY, SPAWNING TIME, AND REPRODUCTIVE OUTPUT IN THE FEMALES OF HAMILTON’S ANCHOVY (THRYSSA HAMILTONII GRAY, 1835)

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Mohammad Mukhlis Kamal ◽  
Yunizar Ernawati ◽  
Nina Nurmalia Dewi
Keyword(s):  
Reproductive Output ◽  
Landing Site ◽  
Maturity Stage ◽  
High Fecundity ◽  
Short Lifespan ◽  
Gonadal Maturity ◽  
Spawning Time ◽  
First Maturity ◽  
Egg Diameter ◽  
Length Frequency Data

Abstract: The Hamilton’s anchovy (Thryssa hamiltonii Gray, 1835) is one of main target species in Indonesian small pelagic fishery. This engraulids member is characterized by short lifespan and fast reproductive cycle. The research aims were to explore the reproduction aspects of the females Hamilton’s anchovy in terms of changes in length at first maturity, spawning seasons, and fecundity as well as egg diameter as reproductive output. Fish was collected weekly during 2009 at fish landing site at Gebang Mekar, Cirebon. The fish was length measured, after which ovaries staged for gonadal maturity stage (GMS), fecundity, and eggs diameter. Length frequency data was all linked to this reproductive aspects. The results showed that Lm was 171.5 ± 1.62 mm, comparable to annual calculation of 171.05 ± 0.01 mm, Lc largely tend to smaller than Lm which indicated to unsustainable fishing. Fish spawns monthly with fecundity range between 3,456 – 15,843 (8,261 ± 2,776 eggs), it might be categorized as high fecundity fish relative to its body size. The distribution of eggs diameter showed 2-3 modus, i.e. they are partial spawner fish. The discrepancies in reproductive ouput is suggested to be influenced by seasons which characterized by different environmental conditions. Keywords: Hamilton’s anchovy, females, length, spawning, reproductive output

scholarly journals The MEDITS maturity scales as a useful tool for investigating the reproductive traits of key species in the Mediterranean Sea

2020 ◽  
Vol 83 (S1) ◽  
pp. 235 ◽  
Author(s):  
Maria Cristina Follesa ◽  
Blondine Agus ◽  
Andrea Bellodi ◽  
Rita Cannas ◽  
Francesca Capezzuto ◽  
...  
Keyword(s):  
Stock Assessment ◽  
Essential Feature ◽  
Reproductive Traits ◽  
Gonadal Development ◽  
Maturity Stage ◽  
Biological Parameters ◽  
Key Species ◽  
Spawning Stock ◽  
First Maturity ◽  
Spawning Periods

Maturity is one of the most important biological parameters used in stock assessment programmes. Indeed, the macroscopic stage of gonadal development is an essential feature in estimating the maturity ogive and spawning stock biomass. It is also useful for determining the spawning season of a species and for monitoring long-term changes in the spawning cycle as well as for many other research needs related to the biology of fish. Despite the efforts made during the last few decades to standardize maturity stage data among all the researchers, marine biologists continue without a manageable and unique maturity scale to describe the reproductive development of fish gonads. For these reasons, the objectives of this article are 1) to investigate the biological parameters of five selected key species (Mullus barbatus, Galeus melastomus, Etmopterus spinax, Aristeus antennatus, Loligo vulgaris) with different reproductive strategies following the macroscopic maturity scales based on the same univocal criteria adopted in the MEDITS programme and described in this work; and 2) to compare them among some Mediterranean geographical sub-areas (GSAs) involved in the programme. Neither spawning periods nor size at first maturity (SFM50) for the studied species showed particular differences in the investigated GSAs.

scholarly journals Photoperiodic induction without light-mediated circadian entrainment in a high arctic resident bird

2020 ◽  
Author(s):  
Daniel Appenroth ◽  
Vebjørn J. Melum ◽  
Alexander C. West ◽  
Hugues Dardente ◽  
David G. Hazlerigg ◽  
...  
Keyword(s):  
Activity Patterns ◽  
High Arctic ◽  
Gonadal Development ◽  
Photoperiodic Response ◽  
Day Length ◽  
The Arctic ◽  
Constant Light ◽  
Constant Darkness ◽  
Polar Regions ◽  
Lagopus Muta

AbstractOrganisms use changes in photoperiod to anticipate and exploit favourable conditions in a seasonal environment. While species living at temperate latitudes receive day length information as a year-round input, species living in the Arctic may spend as much as two-thirds of the year without experiencing dawn or dusk. This suggests that specialised mechanisms may be required to maintain seasonal synchrony in polar regions.Svalbard ptarmigan (Lagopus muta hyperborea) are resident at 74-81° north latitude. They spend winter in constant darkness (DD) and summer in constant light (LL); extreme photoperiodic conditions under which they do not display overt circadian rhythms.Here we explored how arctic adaptation in circadian biology affects photoperiodic time measurement in captive Svalbard ptarmigan. For this purpose, DD-adapted birds, showing no circadian behaviour, either remained in prolonged DD, were transferred into a simulated natural photoperiod (SNP) or were transferred directly into LL. Birds transferred from DD to LL exhibited a strong photoperiodic response in terms of activation of the hypothalamic thyrotropin-mediated photoperiodic response pathway. This was assayed through expression of the Eya3, Tshβ and deiodinase genes, as well as gonadal development. While transfer to SNP established synchronous diurnal activity patterns, activity in birds transferred from DD to LL showed no evidence of circadian rhythmicity.These data show that the Svalbard ptarmigan does not require circadian entrainment to develop a photoperiodic response involving conserved molecular elements found in temperate species. Further studies are required to define how exactly arctic adaptation modifies seasonal timer mechanisms.Summary statementSvalbard ptarmigan show photoperiodic responses when transferred from constant darkness to constant light without circadian entrainment.

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