Patterns of Fish Reproduction at the Interface between Air and Water.

Although fishes by nature are aquatic, many species reproduce in such a way that their embryos are exposed to air either occasionally or constantly during incubation. We examine the ecological context and review specific examples of reproduction by fishes at the air-water interface, including fishes that do and do not breathe air. Four modes of reproduction at the air-water interface are described across 18 teleost orders, from fresh water, estuaries, and sea water.

Hit pause: Developmental arrest in annual killifishes and their close relatives.

Killifishes survive and persist in extreme environments by exploiting both aquatic and terrestrial habitats for egg deposition, and by adjusting the length of development to match availability of water to support larval growth and maturation. Annual killifishes persist in ephemeral bodies of water through the production of drought-tolerant embryos. Survival of the environmental stresses associated with their highly variable and seasonal habitat is supported by their ability to enter into at least two states of metabolic and developmental dormancy, diapause or quiescence.