Reproductive biology in males of the annual killifish Millerichthys robustus (Cyprinodontiformes: Cynolebiidae)

From gametogenesis to spawning: How climate‐driven warming affects teleost reproductive biology

“…Therefore, Sertoli cells continuously interact with germ cells and are essential for the support of spermatogenic cell development ( e.g ., production of growth factor and retinoic acid), survival and physiology as well as phagocytotic functions (Crespo et al ., 2016, 2019; Schulz et al ., 2010). Between cysts, interstitial compartments contain somatic cells and connective tissue, including blood and lymphatics vessels, Leydig cells (involved in androgen synthesis) and nerve fibres (Dadras et al ., 2019; Domínguez‐Castanedo & Uribe, 2019). The successful completion of gametogenesis results in gametes, the quality of which can be defined as the ability of spermatozoa to fertilize an ovum, or an ovum to be fertilized, resulting in the formation of a viable embryo (Bobe & Labbé, 2010).…”

Agonistic interactions with asymmetric body size in two adult‐age groups of the annual killifish Millerichthys robustus (Miller & Hubbs, 1974)

“…This change in strategy could be related to the ecological scenarios faced by fish at their respective ages in temporary water bodies: during the beginning of the flood phase, a young adult annual killifish will have more encounters to fight in the future than an older one at the end of the flood, so the first one has much more to lose if the fight escalates ( e.g ., in terms of energy, time and injuries; Leiser et al ., 2004; Briffa & Sneddon, 2007; Hsu et al ., 2009). Nonetheless, small, older adults have the greatest competitive disadvantage, probably at the worst moment of their lives, because they have little time left (temporary water bodies begin to dry up and resources such as territory and food become increasingly scarce and competed for; Domínguez‐Castanedo & Uribe, 2019; Muñoz‐Campos et al ., 2021). Accordingly, it is expected that small 5‐week‐old males will be less willing to suffer the high‐costs of a prolonged escalation, therefore choosing to finish a contest before a large fish would choose to (Keeley & Grant, 1993).…”

“…The author was particularly interested in the agonistic behavioural process in both sexes of the annual killifish, M. robustus in two ontogenetic stages, corresponding to the following ecological scenarios present along the flood phase in natural temporary water bodies: (a) adult fish 5 weeks post‐hatching (fish this age corresponded to the newly sexually mature fish at the beginning of the flood phase, which is usually registered between the third and fourth weeks post‐hatching in natural populations; Domínguez‐Castanedo et al ., 2017; Domínguez‐Castanedo & Uribe, 2019); and (b) adult fish 24 weeks post‐hatching (this age corresponded to fish that are near to death by pond drought at the end of the flood phase of the temporary water body, which frequently lasts 25–27 weeks; Domínguez‐Castanedo et al ., 2017).…”

“…At the beginning of the rainy season, temporary pools fill with rainwater; nonetheless, the volume of water reduces gradually until they completely dry out for the season (as well as the territories and food available to these species). These environmental dynamics influence changes in the structure of killifish populations that inhabit isolated pools, promoting conditions for competition (Domínguez‐Castanedo & Uribe, 2019; Muñoz‐Campos et al ., 2021). To survive, annual killifishes have evolved complex and time‐changing life‐history strategies to persist permanently in these temporary environments ( e.g ., fast growth rates, early sexual maturation and production of drought‐resistant embryos able to remain in diapause; Podrabsky et al ., 2001; Furness, 2015).…”

From gametogenesis to spawning: How climate‐driven warming affects teleost reproductive biology

“…Therefore, Sertoli cells continuously interact with germ cells and are essential for the support of spermatogenic cell development (e.g., production of growth factor and retinoic acid), survival and physiology as well as phagocytotic functions (Crespo et al, 2016(Crespo et al, , 2019Schulz et al, 2010). Between cysts, interstitial compartments contain somatic cells and connective tissue, including blood and lymphatics vessels, Leydig cells (involved in androgen synthesis) and nerve fibres (Dadras et al, 2019;Domínguez-Castanedo & Uribe, 2019). The successful completion of gametogenesis results in gametes, the quality of which can be defined as the ability of spermatozoa to fertilize an ovum, or an ovum to be fertilized, resulting in the formation of a viable embryo (Bobe & Labbé, 2010).…”