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The provisioning of trophic eggs is exceedingly rare in fish, with only a single example of a species exhibiting this behaviour reported in the scientific literature: the Lake Malawi catfish Bagrus meridionalis. However, observations in captivity suggest that the behaviour is widespread and likely universal among all species within the most species...
Contexts in source publication
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... the pairs had bonded, typical anabantoid mating embracing near the surface was regularly observed among all pairs. Breeding was confirmed by the presence of eggs floating under the water surface in C. pulchra (Figure 1) or from the distended gular region of the mouthbrooding males of C. andrao and C. gachua (Figure 2). ...
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... C. gachua, the male was first observed carrying eggs on 27 March 2019 (Figure 1), the fry were released on 30 March and the first feeding with trophic eggs was observed and filmed the same day (Supplementary video 1). The fry started swimming 3 April. ...
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... C. gachua, the male was first observed carrying eggs on 27 March 2019 (Figure 1), the fry were released on 30 March and the first feeding with trophic eggs was observed and filmed the same day (Supplementary video 1). The fry started swimming 3 April. ...
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... to the release of trophic eggs, females would extend their fins and intensify their body colours, which would induce foraging behaviour in the newly hatched larvae (Supplementary video 1), whereas older free-swimming fry gathered around their mother waiting to be fed (Supplementary video 2). The female then circled above the fry, feeding them with unfertilised eggs (Supplementary videos 1 & 2). ...
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... to the release of trophic eggs, females would extend their fins and intensify their body colours, which would induce foraging behaviour in the newly hatched larvae (Supplementary video 1), whereas older free-swimming fry gathered around their mother waiting to be fed (Supplementary video 2). The female then circled above the fry, feeding them with unfertilised eggs (Supplementary videos 1 & 2). In contrast to fertile eggs (Figure 3(a)), trophic eggs (Figure 3(b)) sank (Supplementary videos 1 & 2), as they lack the large oil globule that normally makes anabantoid eggs buoyant. ...
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... C. pulchra the relatively larger eggs were left floating under the water surface (Figure 1), guarded by both parents, with the male taking the more active role. Parental care continued once the fry hatched, and since the pair continued to produce a new clutch of eggs about once per week for several weeks, the shoal of fry contained siblings of different ages and sizes. ...
Citations
... Also, pregnant father pipefish and seahorses provision lipids and proteins in their brood pouches (Skalkos et al. 2020). Analogous to various anuran lineages (see below), mother bagrid catfish (Bagrus meridionalis) and snakehead fishes (Channa spp.) provision young with unfertilized eggs (McKaye 1986;Weijola 2021). ...
Many animal lineages produce and provision offspring with nutritive material such as milk, lipid-enriched skin, or mucus. Some frogs deposit offspring into small pools of water known as phytotelmata, and a subset of those species also provision offspring with eggs. Often when parental frogs enter the water, oophagous tadpoles swim erratically, vibrate, nip, and even suck on adult skin, which has traditionally been interpreted as begging and tactile stimulus for oviposition. However, these behaviors are also consistent with the hypothesis that such mouth-to-skin contact serves the function of acquiring secretory provisioning from parents, as in the mucophagous fry of some fishes. Here we present images obtained with a macro lens at 6 K resolution of mother-offspring interactions in the strawberry poison frog, Oophaga pumilio, that suggest that tadpoles not only poke or nip maternal skin during feeding visits, but rather forcefully suck on it. We compare these observations to those from numerous lower resolution videos of previous experiments with O. pumilio, and place the findings in the context of a literature review of both anecdotal evidence of mother-tadpole interactions across phytotelm-breeding anurans and secretory provisioning across the animal kingdom. We propose that (1) skin sucking behavior may involve the transfer of nutritive mucous secretions or other defensive, immunological, hormonal, or microbial factors from mother frogs to tadpoles and that (2) such secretions may serve to supplement egg provisioning in this and other frogs with oophagous and phytotelm-dwelling larvae.
