Variation in the Mating System of a Biparental Cichlid Fish, Cichlasoma Panamense

Behaviour ◽  
1985 ◽  
Vol 95 (3-4) ◽  
pp. 181-197 ◽  
Author(s):  
R.J. Wootton ◽  
T.J. Townshend
Keyword(s):  
Game Theory ◽  
Sex Ratio ◽  
Parental Care ◽  
Attack Rate ◽  
Brood Size ◽  
Cichlid Fish ◽  
Dry Season ◽  
Water Levels ◽  
Time Away ◽  
A Current

AbstractCichlasoma panamense is a biparental, substrate-spawning cichlid which breeds during the dry season in Panamanian streams. In one population some males helped to defend their offspring throughout the period of parental care but many deserted their mates to achieve additional spawnings leaving females to guard alone. The proportion of C. panamense guarding in pairs increased throughout the breeding season. This was associated with an increase in the rate with which parental cichlids attacked potential brood predators and an increase in brood size. The increase in attack rate was due to the crowding of fishes as water levels receded during the dry season and especially to the increasing numbers of newly independent cichlids which congregated in the shallow water areas where C. panamense brood. The sex ratio in the population was strongly biased towards females. Males spent more time away from the brood than females which enabled them to find and spawn with unmated females. The attack rate of females brooding alone was not significantly higher than that of those with mates and their foraging rate not significantly lower although they spent less time away from their brood. In a more productive stream where population density was high, breeding was almost entirely in monogamous pairs. The rate at which parents attacked potential predators was higher, the sex ratio was 1:1 and brood size was large. The male's decision to guard or desert appears to depend on his opportunities for further matings, the ability of the female to guard alone and the value of a current brood. These results agree with the predictions of game theory models of parental care.

Brood Size and Offspring Age Affect Risk-Taking and Aggression in Nest-Guarding Common Gobies

Behaviour ◽  
1993 ◽  
Vol 125 (3-4) ◽  
pp. 233-243 ◽  
Author(s):  
Klaus Vestergaard ◽  
Carin Magnhagen
Keyword(s):  
Parental Care ◽  
Risk Taking ◽  
Brood Size ◽  
Male Body ◽  
Male Size ◽  
Zoarces Viviparus ◽  
The Common ◽  
Egg Developmental Stage ◽  
Time Away ◽  
Common Goby

AbstractThe importance of brood size, offspring age, and male size for parental care behaviour was studied in the common goby, Pomatoschistus microps. In field observations, the aggression of nest guarding males was measured as attacks towards a finger when disturbing the nest. Attacking males had larger and more developed clutches compared to non-attacking males, but did not differ in body size. In another set of observations nest guarding males were exposed to a predator (eelpout, Zoarces viviparus) and subsequently chased away from their nests. Time away from the nest decreased significantly with egg developmental stage, i.e. with the time the male had spent guarding a particular brood. However, no correlations with male body length or numbers of eggs in the nest were found. We conclude that male common gobies evaluate future reproductive success by using brood age and brood size as cues for making decisions about risk-taking and aggressive behaviour during parental care.

Population dynamics of Stenothoe valida Dana, 1852 (Amphipoda, Stenothoidae) at Cheongsapo beach of Busan, Republic of Korea

Crustaceana ◽  
2021 ◽  
Vol 94 (4) ◽  
pp. 413-429
Author(s):  
Ye Ji Lee ◽  
Won Gyu Park
Keyword(s):  
Population Dynamics ◽  
Life History ◽  
Sex Ratio ◽  
Brood Size ◽  
Ovigerous Female ◽  
Seasonal Pattern ◽  
Recruitment Rate ◽  
Republic Of Korea ◽  
Female Size ◽  
History Of

Abstract The population dynamics of Stenothoe valida Dana, 1852 were studied at Cheongsapo beach of Busan, Republic of Korea, from March 2019 to March 2020. Sampling was conducted once a month at low tide during spring tides. Specimens were grouped by the cephalic length at 0.025 mm intervals, and classified into four categories: females, ovigerous females, males and juveniles. The sex ratio, defined as females : total males + females, exceeded 0.5 during most of the study period. Brood size was significantly coupled with ovigerous female size. Two to four cohorts appeared at each study period. New cohorts occurred at almost every sampling except in the samples Jun-2, and Nov-2. Life span was estimated at 1-2 months. The juvenile ratio, the ratio of ovigerous females, and the recruitment rate estimated by FiSAT were commonly high in summer and winter. The life history of S. valida was not coupled with water temperature, but had a strong seasonal pattern.

scholarly journals Offspring telomere length in the long lived Alpine swift is negatively related to the age of their biological father and foster mother

2017 ◽  
Vol 13 (9) ◽  
pp. 20170188 ◽  
Author(s):  
François Criscuolo ◽  
Sandrine Zahn ◽  
Pierre Bize
Keyword(s):  
Parental Care ◽  
Telomere Length ◽  
Brood Size ◽  
Foster Parents ◽  
Growth Conditions ◽  
Early Growth ◽  
Foster Mother ◽  
Biological Father ◽  
Accumulation Of Damage ◽  
Older Males

A growing body of studies is showing that offspring telomere length (TL) can be influenced by the age of their parents. Such a relationship might be explained by variation in TL at conception (gamete effect) and/or by alteration of early growth conditions in species providing parental care. In a long-lived bird with bi-parental care, the Alpine swift ( Apus melba ), we exchanged an uneven number of 2 to 4-day-old nestlings between pairs as part of a brood size manipulation. Nestling TL was measured at 50 days after hatching, which allowed investigation of the influence of the age of both their biological and foster parents on offspring TL, after controlling for the manipulation. Nestling TL was negatively related to the age of their biological father and foster mother. Nestling TL did not differ between enlarged and reduced broods. These findings suggest that offspring from older males were fertilized by gametes with shorter telomeres, presumably due to a greater cell division history or a longer accumulation of damage, and that older females may have provided poorer parental care to their offspring.

scholarly journals Galanin neuron activation in feeding, parental care, and infanticide in a mouthbrooding African cichlid fish

2020 ◽  
Vol 126 ◽  
pp. 104870
Author(s):  
Julie M. Butler ◽  
Erandi M. Herath ◽  
Arohan Rimal ◽  
Sarah M. Whitlow ◽  
Karen P. Maruska
Keyword(s):  
Parental Care ◽  
Cichlid Fish ◽  
African Cichlid ◽  
Neuron Activation

scholarly journals Response of wild mammals to seasonal shrinking-and-expansion of habitats due to flooding regime of the Pantanal, Brazil

2006 ◽  
Vol 66 (4) ◽  
pp. 991-998 ◽  
Author(s):  
S. B. Mamede ◽  
C. J. R. Alho
Keyword(s):  
Dry Season ◽  
Water Levels ◽  
Wild Mammals ◽  
Flooding Regime ◽  
Terrestrial Mammals ◽  
Paraguay River ◽  
Terrestrial Habitats ◽  
Slow Moving ◽  
Blastocerus Dichotomus ◽  
Seasonally Flooded

The Pantanal is a large savanna wetland (138,183 km² in Brazil), important for its wildlife, fed by tributaries of the upper Paraguay River, center of South America (Brazil, touching Bolivia and Paraguay). Uplands are plateaus (250-1,200 m high, 215,000 km² in Brazil) and flatland is the Pantanal (80-150 m high, 147,574 km² in Brazil). Rivers are slow moving when they meet the flatland (slope 0.3-0.5 m/km east-west; 0.03-0.15 m/km north-south), periodically overflowing their banks, creating a complex seasonal habitat range. Recurrent shallow flooding occupies 80% of the Pantanal; during the dry season flooded areas dry up. Fluctuating water levels, nutrients and wildlife form a dynamic ecosystem. A flooding regime forms distinct sub-regions within the Pantanal. A mammal survey was carried out in the sub-region of the Rio Negro from April, 2003 through March, 2004 to study the diversity and abundance of terrestrial mammals during the dry and flooding seasons. A total of 36 species were observed in the field. The capybara Hydrochaeris hydrochaeris was the most frequent species, followed by the crab-eating-fox Cerdocyon thous and the marsh deer Blastocerus dichotomus. The highest abundance of species was observed during the dry season (August and September), when there is a considerable expansion of terrestrial habitats, mainly seasonally flooded grassland. Animal abundance (in terms of observed individual frequencies) varied during the dry and wet seasons and the seasonally flooded grassland was the most utilized habitat by mammals in the dry season.

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