Medaka (Oryzias latipes) initiate courtship and spawning late at night: Insights from field observations

PLoS ONE, Journal Year: 2025, Volume and Issue: 20(2), P. e0318358 - e0318358

Published: Feb. 12, 2025

Laboratory experiments were conducted using model organisms to elucidate biological phenomena. However, the natural habitats of are inherently more complex than those found in laboratory. To complement laboratory experiments, we field observations small freshwater fish medaka ( Oryzias latipes ), widely used as a organism, its ecology and behavior environments. Our results showed that initiated courtship spawning late at night, much earlier previously thought. Nocturnal video examining time during breeding season Gifu, Japan (sunset: 19:00; sunrise: 5:00) revealed presence post-spawning females around midnight. Behavioral analysis was inactive until 23:00, with activity increasing from 0:00 peaking 1:00 3:00. Furthermore, significant increase male observed between 4:00. These findings provide first empirical evidence mating begins significantly reported laboratory, within an hour before or after light onset morning. This study highlights importance revealing critical aspects organismal biology may be overlooked settings.

Language: Английский

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Temporal dynamics of courtship and spawning in medaka under laboratory conditions revealed by 24-hour video monitoring: comparisons with natural environments

Published: May 12, 2025

Understanding the biological phenomena in model organisms typically relies on laboratory studies. However, ecological validity of these findings is often uncertain when natural behaviors remain understudied. Medaka (Oryzias latipes) a widely used reproductive and behavioral research, but timing its spawning settings has rarely been directly observed. Recent fieldwork suggested that medaka spawn several hours before sunrise, contrasting with common laboratory-based assumption occurs within an hour or after light exposure. In this study, we conducted continuous 24-h video recordings pairs under controlled conditions (14L:10D photoperiod) to quantify diel variations courtship behavior. Spawning occurred mostly between 08:00 11:00, peaking just lights-on (08:00). Courtship behavior began during dark period, increased lights-on, peaked 07:00 09:00. These patterns mirrored field observations showed consistent temporal lag conditions. This shift likely reflects differences photoperiod timing, lack gradual transitions, stable water temperatures. Our underscore importance designing experimental protocols informed by dynamics, ensuring more accurate inferences other organisms.

Language: Английский

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The importance of detailed observations of behaviour and natural history for generating and answering novel questions

Animal Behaviour, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 1, 2024

Language: Английский

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Mating behaviour of endemic and introduced Galapaganus weevils (Coleoptera: Curculionidae) in the Galápagos Islands: linking behavioural mechanism to genomic pattern

Animal Behaviour, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 1, 2024

Language: Английский

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Pristionchus – Beetle associations: Towards a new natural history

Journal of Invertebrate Pathology, Journal Year: 2024, Volume and Issue: unknown, P. 108243 - 108243

Published: Dec. 1, 2024

The free-living nematode Pristionchus pacificus has been established as a model system in integrative evolutionary biology by combining laboratory studies with field work and biology. Multiple genetic, molecular experimental tools collection of more than 2,500P. strains 50 species, which are available living cultures or frozen stock collections, support research on various life history traits. Species exhibit number complex traits unknown from Caenorhabditis elegans most other nematodes. First, P. can form two alternative mouth forms, an example developmental plasticity that is increasingly studied to investigate the role facilitator novelty. More decade identified associated genetic epigenetic mechanisms revealed ecological significance feeding structure plasticity. Second, one morphs results predatory behavior against nematodes currently used neurobiology predation. Third, potential predation risk cannibalism among conspecifics. Strikingly, have developed self-recognition allows distinction self (kin) non-self. Given all these organismal features, this recently considered key for towards new natural (West-Eberhard, 2024). Here, I summarize recent focus 'new history'. In addition, review some indicate interaction EPNs was suggested based surveys different habitats.

Language: Английский

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