scholarly journals Sex-Specific Routes to Independent Breeding in a Polygynous Cooperative Breeder

2021 ◽  
Vol 9 ◽  
Author(s):  
Dario Josi ◽  
Jana M. Flury ◽  
Maria Reyes-Contreras ◽  
Hirokazu Tanaka ◽  
Michael Taborsky ◽  
...  
Keyword(s):  
Life History ◽  
Growth Rates ◽  
Sexual Maturity ◽  
Life History Strategies ◽  
Dominant Male ◽  
Dispersal Patterns ◽  
Major Life ◽  
Mating Patterns ◽  
Cooperatively Breeding ◽  
Fitness Benefits

How can individuals obtain a breeding position and what are the benefits associated with philopatry compared to dispersal? These questions are particularly intriguing in polygamous cooperative breeders, where dispersal strategies reflect major life history decisions, and routes to independent breeding may utterly differ between the sexes. We scrutinized sex-dependent life-history routes by investigating dispersal patterns, growth rates and mortality in a wild colony of the cooperatively breeding cichlid Neolamprologus savoryi. Our data reveal that female helpers typically obtain dominant breeding positions immediately after reaching sexual maturity, which is associated with strongly reduced growth. In contrast, males obtain breeder status only at twice the age of females. After reaching sexual maturity, males follow one of two strategies: (i) they may retain their subordinate status within the harem of a dominant male, which may provide protection against predators but involves costs by helping in territory maintenance, defence and brood care; or (ii) they may disperse and adopt a solitary status, which diminishes survival chances and apparently reflects a best-of-a-bad-job strategy, as there are no obvious compensating future fitness benefits associated with this pathway. Our study illustrates that sex-dependent life history strategies strongly relate to specific social structures and mating patterns, with important implications for growth rates, the age at which breeding status is obtained, and survival.

scholarly journals Life-history strategies associated to reproduction of three Hyphessobrycon species (Characidae) in lentic environments of upper Paraná River basin

2013 ◽  
Vol 25 (4) ◽  
pp. 398-405 ◽  
Author(s):  
Cristina da Silva Gonçalves ◽  
Ursulla Pereira Souza ◽  
Fabio Cop Ferreira ◽  
Alexandre Peressin ◽  
Francisco Manoel de Souza Braga
Keyword(s):  
Life History ◽  
River Basin ◽  
Sexual Maturity ◽  
Life History Strategies ◽  
Oxbow Lakes ◽  
Parana River ◽  
Three Samples ◽  
Size At Sexual Maturity ◽  
Upper Paraná River ◽  
Upper Paraná River Basin

AIM: Life-history strategies in fish include essential parameters related to offspring survivorship, fecundity and time of reproduction, which represent adaptive traits that enable a species to deal with spatial and temporal variability of abiotic conditions. This study aimed to compare reproductive traits associated to life-history theory for three Hyphessobrycon species from two lentic environments (four natural oxbow lakes and a man-made reservoir) of Mogi Guaçu River, upper Paraná River basin. METHODS: Specimens were collected with four minnow traps between August 2005 and July 2006 to cover dry and wet seasons (three samples in each season, and three samples in each environment). RESULTS: Reproductive strategy of H. bifasciatus and H. eques, which predominated in the oxbow lakes, differed from H. anisitsi in the reservoir. Hyphessobrycon bifasciatus and H. eques were single spawners with lower fecundity and size at sexual maturity, but invested more in number of eggs per body gram, while H. anisitsi was a multiple spawner species with higher fecundity, larger size at sexual maturity and body size. CONCLUSIONS: In seasonal environments, single spawners are synchronized with the floods to maximize juvenile survivorship, while reservoirs harbors multiple spawners’ fish due to the reduced fluctuation between high and low floods resulting from dam operation. Therefore, the seasonal condition in the oxbow lakes due to the flood pulse favored single spawners’ tactic, as showed by H. bifasciatus and H. eques. In contrast, the multiple spawning of H. anisitsi seems to be related to the more stable environmental condition throughout the year provided by the dam. Life-histories reported herein to Hyphessobrycon species must be common to other characid fishes inhabiting similar environments.

scholarly journals Life history traits of the temperate mini-maximalist Idiosepius notoides, (Cephalopoda: Sepioidea)

2003 ◽  
Vol 83 (6) ◽  
pp. 1297-1300 ◽  
Author(s):  
Sean R. Tracey ◽  
Mike A. Steer ◽  
Gretta T. Pecl
Keyword(s):  
Life History ◽  
Growth Rates ◽  
Sexual Maturity ◽  
Life History Traits ◽  
Mantle Length ◽  
Power Curve ◽  
Short Life ◽  
Gender Dimorphism ◽  
Cephalopod Species

Age, growth and maturation of the temperate ‘mini-maximalist’ Idiosepius notoides from Tasmania is described and compared with those of its tropical congener Idiosepius pygmaeus. Using statolith increment analysis, growth of I. notoides was best described by a power curve with a maximum age of 115 days recorded. Males have a shorter lifespan than females, however growth rates were similar between the sexes. Idiosepius notoides grows to a larger size than its tropical counterpart. Onset of maturity in I. notoides occurred at an age of approximately 68 days for males and 88 days for females compared to 45–60 days for I. pygmaeus. Size at onset of sexual maturity was analogous between the two species, with males mature at approximately 6·5 mm mantle length (ML) and females at 14·0 mm ML. Idiosepius notoides, like I. pygmaeus, is a small short-lived sepioid with significant gender dimorphism and the capacity to spawn multiple times throughout its short life. This research supports the concept of similar cephalopod species living longer and growing larger in cooler environments.

Relative growth, life-history phases, and sexual maturity of American lobster (Homarus americanus)

2010 ◽  
Vol 88 (4) ◽  
pp. 347-358 ◽  
Author(s):  
Kim Émond ◽  
Bernard Sainte-Marie ◽  
Louise Gendron
Keyword(s):  
Life History ◽  
Sexual Maturity ◽  
Body Part ◽  
Homarus Americanus ◽  
American Lobster ◽  
Body Parts ◽  
Growth Phases ◽  
Major Life ◽  
Relative Growth ◽  
Cephalothorax Length

Previous studies of relative growth in crustaceans have focused primarily on body parts representing sexual characters for the purpose of determining size at onset of sexual maturity. We have revisited the relative growth of abdomen and crusher claw in American lobster ( Homarus americanus H. Milne Edwards, 1837) in a general life-history perspective using a broad spectrum of lobster sizes (6–160 mm cephalothorax length (CL)). Growth phases were recognized by inflections in scatterplots of a body-part measurement against CL. The abdomen is characterized by three growth phases in the male and female, whereas the crusher claw has at least three growth phases in the male and at least two in the female. Additionally, we explored relative growth of gonopod and vas deferens for males of 35–150 mm CL. Both organs exhibit a synchronous change from strong to weak positive growth allometry. The growth phases can be associated with major life-history events including the transition from a cryptic to an overt lifestyle and the onset of physiological, functional, and morphometric maturity. The onset of morphometric maturation inferred from relative growth of abdomen and crusher claw precedes functional maturity in females and follows it in males.

scholarly journals Moonlight enhances growth in larval fish

2020 ◽  
Author(s):  
Jeffrey Shima ◽  
SE Swearer
Keyword(s):  
Life History ◽  
Growth Rates ◽  
Larval Fish ◽  
Fish Larvae ◽  
Larval Growth ◽  
Negative Influence ◽  
Life History Strategies ◽  
Foraging Efficiency ◽  
Daily Growth ◽  
Pelagic Larvae

© 2018 by the Ecological Society of America Moonlight mediates trophic interactions and shapes the evolution of life-history strategies for nocturnal organisms. Reproductive cycles and important life-history transitions for many marine organisms coincide with moon phases, but few studies consider the effects of moonlight on pelagic larvae at sea. We evaluated effects of moonlight on growth of pelagic larvae of a temperate reef fish using “master chronologies” of larval growth constructed from age-independent daily increment widths recorded in otoliths of 321 individuals. We found that daily growth rates of fish larvae were enhanced by lunar illumination after controlling for the positive influence of temperature and the negative influence of cloud cover. Collectively, these results indicate that moonlight enhances growth rates of larval fish. This pattern is likely the result of moonlight's combined effects on foraging efficiency and suppression of diel migrations of mesopelagic predators, and has the potential to drive evolution of marine life histories.

scholarly journals Moonlight enhances growth in larval fish

2020 ◽  
Author(s):  
Jeffrey Shima ◽  
SE Swearer
Keyword(s):  
Life History ◽  
Growth Rates ◽  
Larval Fish ◽  
Fish Larvae ◽  
Larval Growth ◽  
Negative Influence ◽  
Life History Strategies ◽  
Foraging Efficiency ◽  
Daily Growth ◽  
Pelagic Larvae

© 2018 by the Ecological Society of America Moonlight mediates trophic interactions and shapes the evolution of life-history strategies for nocturnal organisms. Reproductive cycles and important life-history transitions for many marine organisms coincide with moon phases, but few studies consider the effects of moonlight on pelagic larvae at sea. We evaluated effects of moonlight on growth of pelagic larvae of a temperate reef fish using “master chronologies” of larval growth constructed from age-independent daily increment widths recorded in otoliths of 321 individuals. We found that daily growth rates of fish larvae were enhanced by lunar illumination after controlling for the positive influence of temperature and the negative influence of cloud cover. Collectively, these results indicate that moonlight enhances growth rates of larval fish. This pattern is likely the result of moonlight's combined effects on foraging efficiency and suppression of diel migrations of mesopelagic predators, and has the potential to drive evolution of marine life histories.

scholarly journals Ontogenetic changes in the elemental composition and stoichiometry of marine copepods with different life history strategies

2020 ◽  
Vol 42 (3) ◽  
pp. 320-333 ◽  
Author(s):  
Enric Saiz ◽  
Kaiene Griffell ◽  
Albert Calbet
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Elemental Composition ◽  
Growth Rates ◽  
Stoichiometric Composition ◽  
Maximum Growth ◽  
Life History Strategies ◽  
Ontogenetic Variation ◽  
Ontogenetic Changes ◽  
P Content

Abstract We describe the ontogenetic variation in elemental and stoichiometric composition of two copepod species with very contrasted life history patterns, the calanoid Paracartia grani and the cyclopoid Oithona davisae. The first species is a broadcasting, highly productive copepod, whereas the latter is an egg-carrying copepod, much less productive. We reared cultures of both species under conditions of excess food and analyzed their C, N and P composition, and their molar ratios, along development. Both species differed on their specific P content, whereas the specific C and N content were similar. As expected, the specific P content of P. grani was higher, resulting in lower C:P and N:P ratios. Furthermore, we compared our elemental composition data with previously reported stage-specific (nauplii and adult female) maximum growth rates of these two species. We found that for O. davisae, the ontogenetic variation in specific P content agreed with the reported differences in growth rate along development; however, in the case of P. grani, in which juvenile and adult maximum growth rates are similar, the variations in specific P content along development did not reflect the growth rate pattern.

Geographic effects on American eel (Anguilla rostrata) life history characteristics and strategies

2010 ◽  
Vol 67 (2) ◽  
pp. 326-346 ◽  
Author(s):  
B. M. Jessop
Keyword(s):  
Life History ◽  
Growth Rates ◽  
Atlantic Coast ◽  
Life History Strategies ◽  
Anguilla Rostrata ◽  
Annual Growth Rate ◽  
Degree Days ◽  
Silver Eel ◽  
American Eel ◽  
Spawning Site

Latitudinal variability in length and age at maturity and annual growth rate for the American eel ( Anguilla rostrata ) along the Atlantic coast of North America was examined with respect to life history strategies and theory. Maturing (silver phase) female lengths and ages increased with increasing latitude (and distance) from the Sargasso Sea spawning site, as did male ages but not lengths. Growth rates for females (and males) declined with increasing latitude south of 44°N latitude, approximately the entrance to the Cabot Strait, but were constant or increased within the Gulf of St. Lawrence and St. Lawrence River, depending on the analysis method. The growing season and the number of degree-days ≥ 10 °C declined with increasing latitude. Female growth rates adjusted for the number of degree-days were approximately constant south of 44°N but increased further north, suggesting countergradient variation in growth. The temperature–size rule (increase in body size at lower temperatures) evidently applies to American eel females, but not males. No current life history model provides a satisfactory explanatory mechanism for the temperature–size rule and for anguillid life history strategies. A genetic link is proposed between increasing age (length) at elver and silver eel stages with increasing distance from the spawning area.

Do phosphorus requirements for RNA limit genome size in crustacean zooplankton?

Genome ◽  
2008 ◽  
Vol 51 (9) ◽  
pp. 685-691 ◽  
Author(s):  
Dag O. Hessen ◽  
Marc Ventura ◽  
James J. Elser
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Body Size ◽  
Genome Size ◽  
Growth Rates ◽  
Life History Strategies ◽  
Crustacean Zooplankton ◽  
Limited Growth ◽  
P Deficiency ◽  
Small Genome

As for most other organisms, genome size in zooplankton differs widely. This may have a range of consequences for growth rate, development, and life history strategies, yet the causes of this pronounced variability are not settled. Here we propose that small genome size may be an evolutionary consequence of phosphorus (P) allocation from DNA to RNA under P deficiency. To test this hypothesis we have compared the two major groups of zooplankton, copepods and cladocerans, that have overlapping niches and body size. Relative to the cladocerans, copepods have a more complex life history and a lower mass-specific P content, while cladocerans tend to have higher P and RNA contents and higher specific growth rates and frequently experience P-limited growth, likely due to a shortage of P for ribosome synthesis. Cladocerans also generally have smaller genomes than copepods (1C = 0.17–0.63 pg DNA·cell–1 vs. 1C = 0.10–10 pg DNA·cell–1). Furthermore, cladocerans have a higher slope of the relationship of body size with DNA content (1.5 vs. 0.28 in copepods) and present almost 15-fold higher RNA:DNA ratios (24.8 in cladocerans vs. 1.6 in copepods). Hence, small genome size in cladocerans could reflect an evolutionary pressure towards “efficient” genomes to conserve a key element needed to maximize growth rate. We do not claim that this is a universal cause of genome size variability, but propose that streamlining of genomes could be related to P conservation rather than energy conservation. This could be relevant for a range of organisms that may suffer P-limited growth rates.

scholarly journals Empirical evidence of plasticity in life-history characteristics across climatic and fish density gradients

2017 ◽  
Vol 74 (4) ◽  
pp. 464-474 ◽  
Author(s):  
Hillary G.M. Ward ◽  
John R. Post ◽  
Nigel P. Lester ◽  
Paul J. Askey ◽  
Theresa Godin
Keyword(s):  
Life History ◽  
Empirical Evidence ◽  
Growth Rates ◽  
Life History Theory ◽  
Resource Competition ◽  
Somatic Growth ◽  
Life History Strategies ◽  
Fish Density ◽  
Density Gradients ◽  
Life History Characteristics

Understanding how environmental productivity and resource competition influence somatic growth rates and plasticity in life-history traits is a critical component of population ecology. However, evolutionary effects often confound the relationship between plasticity in life-history characteristics and environmental productivity. We used a unique set of experimentally stocked populations of rainbow trout (Oncorhynchus mykiss) to empirically test predictions from life-history theory relating to patterns in immature growth rates, age- and size-at-maturity, and the energy allocated into reproduction across climatic and fish density gradients. Our results support theoretical predictions that plasticity in life-history characteristics is a function of environmental variables. In particular, we demonstrate that immature growth rates are best explained by climatic and density-dependent competition effects and that age-at-maturity and the energy allocated to reproduction depends on juvenile growth conditions. Empirical evidence of these relationships helps to improve our understanding of optimal life-history strategies of fish populations.

scholarly journals Cryptic alternative male mating strategies in invasive alien round goby (Neogobius melanostomus) of the upper Danube River

2020 ◽  
Author(s):  
Alexander F. Cerwenka ◽  
Joerg Brandner ◽  
Juergen Geist ◽  
Ulrich K. Schliewen
Keyword(s):  
Life History ◽  
Sexual Maturity ◽  
Round Goby ◽  
Trophic Niche ◽  
Mating Strategies ◽  
Neogobius Melanostomus ◽  
Danube River ◽  
Life History Strategies ◽  
Male Mating ◽  
Male Mating Strategies

Abstract Male alternative mating strategies are a widespread life history choice, yet they have hardly been assessed in the context of fish invasions. As established proxies for alternative life-history strategies, body length and sexual maturity of Ponto–Caspian round goby (Neogobius melanostomus) from the recently invaded upper Danube River were contrasted and differential trophic niche occupation was assessed. Only about 4% of analyzed gobies qualified as potential sneakers which may be explained by the recent and ongoing invasion process. This study provides evidence for the occurrence of sneaking behavior of invasive round goby in the upper Danube River.

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