reproduction

Mouthbrooding

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Eyed eggs in a mouthbrooder (photo credit: The Fish Room).

Guest post: Gretchen Stokes, University of Florida

Mouthbrooding is when fertilized eggs are carried and incubated in the parent’s mouth.  Rather sophisticated for parental care in fishes, it may have evolved from lack of nest sites, predation or habitat invasion.  It occurs in more than 53 genera of fishes.  Mouthbrooding can be conducted by males (paternal), females (maternal) or both.  While more commonly female, parental care by males occurs in some well-known species, including snakeheads and arowana.  Parental feeding is fairly or fully restricted during incubation, as swallowing or chewing could harm egg development.  Brood parasitism can also occur, where a parasitic fish attacks the brooder’s eggs and leaves behind the fertilized eggs for care by the mouthbrooder (e.g. mochokid catfish eggs incubated in cichlid parent’s mouths).

Fry

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Coho Salmon fry (photo credit: City of Surrey).

Guest post: Gretchen Stokes, University of Florida

Fry refers to a life (growth) stage of fishes that are recently hatched.  This is generally after the yolk sac has been absorbed and almost or entirely disappeared.  At this point, the swim bladder is typically functional and fish can actively feed for themselves.  Depending on the species, this stage can last a few months or more until scales develop.  Fry can be thought of as the “infant” stage for fishes.  Because of their small size at this stage (often only a few centimeters), fry are vulnerable to predation in this stage and need shallow, protected habitat to feed and grow.