MORPHOFUNCTIONAL CHARACTERISTICS OF GONAD OF THE GABLE-ROLL NEOGOBIUS MELANOSTOMUS (PALLAS, 1814) OF THE LOWER NISTRY DURING THE SPAWN

The results of studies of the reproductive system of sexually mature females of the round goby Neogobius melanostomus (Pallas, 1814) from the Lower Dniester during the spawning season are presented. The age of sexual maturation and the timing of spawning of fish in the conditions of this basin are determined. Asynchrony in the development of germ cells has been identified, which provides four-time spawning during the entire breeding season of fish. Throughout the entire reproductive cycle, larger females with greater body weight and gonad mass are the first to spawn.

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Changes in body size in fluctuating populations of the collared lemming: age and photoperiod influences

Canadian Journal of Zoology ◽

10.1139/z81-031 ◽

1981 ◽

Vol 59 (2) ◽

pp. 174-182 ◽

Cited By ~ 15

Author(s):

Frank F. Mallory ◽

J. Richard Elliott ◽

Ronald J. Brooks

Keyword(s):

Body Weight ◽

Body Size ◽

Breeding Season ◽

Sexual Maturation ◽

Population Fluctuations ◽

Total Variability ◽

And Shifts ◽

Fluctuating Populations ◽

Best Fit

Paired wet lens weights of 115 laboratory-reared collared lemmings were plotted against known age, to assess the reliability of this parameter, as a means of estimating age. Approximately 85% of the total variability in In age (A) was accounted for by In paired wet lens weight (W) (equation of best fit; In A (days) = −0.9771 + 2.186 In W (milligrams). In addition, variation in gender and photoperiod did not influence lens weight, although other parameters such as body weight and pelage were significantly affected.Field data from Eskimo Point, N. W.T., indicated that animals were older and heavier during the peak year (1973). Reduced recruitment and length of breeding season were observed during high densities, and sexual maturation was delayed in the nonbreeding segment of the population. Fluctuations in body size during microtine cycles were discussed as influenced by age, photoperiod, and shifts in the breeding season.

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Changes in brain arginine vasotocin, isotocin, plasma 11-ketotestosterone and cortisol in round goby, Neogobius melanostomus, males subjected to overcrowding stress during the breeding season

Comparative Biochemistry and Physiology Part A Molecular & Integrative Physiology ◽

10.1016/j.cbpa.2013.03.018 ◽

2013 ◽

Vol 165 (2) ◽

pp. 237-242 ◽

Cited By ~ 16

Author(s):

Ewa Sokołowska ◽

Agnieszka Kleszczyńska ◽

Hanna Kalamarz-Kubiak ◽

Bartłomiej Arciszewski ◽

Ewa Kulczykowska

Keyword(s):

Breeding Season ◽

Round Goby ◽

Neogobius Melanostomus ◽

Arginine Vasotocin

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Effects of ageing and exogenous melatonin on pituitary responsiveness to GnRH in rats

Reproduction ◽

10.1530/reprod/119.1.151 ◽

2000 ◽

pp. 151-156 ◽

Cited By ~ 12

Author(s):

E Diaz ◽

D Pazo ◽

AI Esquifino ◽

B Diaz

Keyword(s):

Body Weight ◽

Reproductive System ◽

Plasma Concentrations ◽

Pituitary Hormones ◽

Female Rats ◽

Control Groups ◽

Melatonin Treatment ◽

Exogenous Melatonin ◽

Reproductive Axis ◽

Effect Of Age

The effect of age and melatonin on the activity of the neuroendocrine reproductive system was studied in young cyclic (3-5 months-old), and old acyclic (23-25 month-old) female rats. Pituitary responsiveness to a bolus of GnRH (50 ng per 100 g body weight) was assessed at both reproductive stages in control and melatonin-treated (150 micrograms melatonin per 100 g body weight each day for 1 month) groups. After this experiment, female rats were treated for another month to study the influence of ageing and melatonin on the reproductive axis. Plasma LH, FSH, prolactin, oestradiol and progesterone were measured. A positive LH response to GnRH was observed in both control groups (cyclic and acyclic). However, a response of greater magnitude was observed in old acyclic rats. Melatonin treatment reduced this increased response in acyclic rats and produced a pituitary responsiveness similar to that of young cyclic rats. FSH secretion was independent of GnRH administration in all groups, indicating desynchronization between LH and FSH secretion in response to GnRH in young animals and during senescence. No effect on prolactin was observed. Significantly higher LH (3009.11 +/- 1275.08 pg ml(-1); P < 0.05) and FSH concentrations (5879.28 +/- 1631.68 pg ml(-1); P < 0.01) were seen in acyclic control rats. After melatonin treatment, LH (811.11 +/- 89.71 pg ml(-1)) and FSH concentrations (2070 +/- 301.62 pg ml(-1)) decreased to amounts similar to those observed in young cyclic rats. However, plasma concentrations of oestradiol and progesterone were not reduced. In conclusion, the results of the present study indicate that, during ageing, the effect of melatonin is exerted primarily at the hypothalamo-pituitary axis rather than on the ovary. Melatonin restored the basal concentrations of pituitary hormones and pituitary responsiveness to similar values to those observed in young rats.

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Morphometric variability in round goby Neogobius melanostomus (Perciformes: Gobiidae) from the Sea of Azov

Zoosystematica Rossica ◽

10.31610/zsr/2017.26.2.392 ◽

2017 ◽

Vol 26 (2) ◽

pp. 392-405 ◽

Cited By ~ 1

Author(s):

O.A. Diripasko ◽

T.A. Zabroda

Keyword(s):

Round Goby ◽

Joint Effect ◽

Neogobius Melanostomus ◽

Sea Of Azov ◽

Morphometric Characters ◽

One Dimensional ◽

The Sea Of Azov ◽

Size Dependent ◽

Size Variability ◽

Males And Females

A total of 38 morphometric characters of the round goby Neogobius melanostomus melanostomus (Pallas, 1814) were studied in its native range in the Sea of Azov. The aim was to assess joint effect of sexual dimorphism and size variability on overall variability within groups of samples (populations) using appropriate methods of traditional statistical analysis (one-dimensional and multivariate statistics). Sex and size-dependent variability was studied based on model samples of males and females of different size. Most of the studied morphometric characters of round goby from the Sea of Azov demonstrated statistically significant sex- and size-dependent in-group variability. The pattern of the variability suggests that, for a comparison of round goby from different sea regions and between populations, separate samples of males and females within the range 9–13 cm SL should be examined in order to minimise the effect of the size and sex factors. The approach of searching for the most informative size range could be useful not only for further studies of infraspecific variation but for comparisons between morphologically close gobiin species.

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Genetic architecture of body weight, condition factor and age of sexual maturation in Icelandic Arctic charr (Salvelinus alpinus)

Molecular Genetics and Genomics ◽

10.1007/s00438-011-0628-x ◽

2011 ◽

Vol 286 (1) ◽

pp. 67-79 ◽

Cited By ~ 31

Author(s):

Eva Küttner ◽

Hooman K. Moghadam ◽

Skúli Skúlason ◽

Roy G. Danzmann ◽

Moira M. Ferguson

Keyword(s):

Body Weight ◽

Sexual Maturation ◽

Genetic Architecture ◽

Condition Factor ◽

Salvelinus Alpinus ◽

Arctic Charr ◽

Weight Condition

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Feeding activity and diet composition of round goby (Neogobius melanostomus, Pallas 1814) in the coastal waters of SE Baltic Sea

Oceanological and Hydrobiological Studies ◽

10.1515/ohs-2015-0048 ◽

2015 ◽

Vol 44 (4) ◽

Cited By ~ 7

Author(s):

Artūras Skabeikis ◽

Jūratė Lesutienė

Keyword(s):

Baltic Sea ◽

Coastal Waters ◽

Diet Composition ◽

Feeding Activity ◽

Macoma Balthica ◽

Round Goby ◽

Benthic Fauna ◽

Neogobius Melanostomus ◽

The Body ◽

Gut Contents

AbstractFeeding activity and diet composition of round goby were investigated in the south-eastern Baltic Sea, the Lithuanian coastal waters during May-October 2012 in order to determine main feeding objects and seasonal periods when native fauna could be most affected by predation of this highly invasive species. In total, prey represented by 18 taxa was found in the gut contents of dissected fish. Feeding activity of round goby varied depending on the body size, sex and stage of the reproduction period. The gut contents of < 50 mm specimens were dominated by zooplanktonic and meiobenthic organisms, whereas larger individuals (50–99 mm) shifted to amphipods and mollusks. Individuals of the intermediate 100-200 mm length had a variable diet, changing depending on the season; in spring they mostly preyed on Macoma balthica, in summer − on polychaetes, while in autumn the contribution of Mytilus trossulus and fish considerably increased in their diet. Diet composition of individuals ≥ 200 mm was relatively constant in the course of the study with substantial preference to M. balthica. These findings imply that benthic fauna, particularly a newly settled generation of epibenthic mollusks in autumn is under strong predatory pressure of the round goby.

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