Guest post: Bonnie Myers, North Carolina State University, USGS Substrate in streams, rivers, lakes, and the ocean creates important fish habitat and plays an important role in multiple fish life history processes, daily activity, and prey availability. Substrate in aquatic habitats consists of surface and subsurface materials in the streambed, riverbed, or ocean bottom with different fish … [Read more…]
Guest post by Emily Argo Each year adult salmon migrate upstream to spawn (lay eggs) putting into motion their offsprings’ journey from hatching to making their way back to the ocean as juveniles. In addition to being a spectacular event to witness, these migrations also play a central role in ecosystem health. Over 100 different … [Read more…]
A scute is an external bony plate on the surface of a fish. Scutes serve a protective function, acting as a body armor for fish against environmental abrasions and even predation. In some fishes, such as Alewife (Alosa pseudoharengus), scutes are a row of scales modified into sharp, protective plates. In other fishes, like Shovelnose … [Read more…]
The swim bladder is an air filled organ used by some fish to maintain buoyancy at a desired depth and produce or hear sound. Physostomous swim bladders are directly connected to the gastrointestinal tract so that fish with these swim bladders, such as herrings, must “gulp” air to inflate their swim bladder and “burb” or … [Read more…]
In contrast to eurytherms, senothermic fish can only function in a narrow range of water temperatures. Brook Trout (Salvelinus fontinalis), for example, function optimally approximately between 13 and 18 degrees Celsius. This thermoregulatory strategy requires that organs, enzymes, and metabolic processes operate in a small temperature band and makes these fish particularly vulnerable to environmental changes. … [Read more…]
Happy Halloween! Schreckstoff, German for “scary stuff,” is a chemical compound, glycosaminoglycan chondroitin, that some fish species release when they are injured. This “take-one -for-the-team” signal lets their conspecifics know that there is danger in the area. But more than just an alarm signal, Schreckstoff also serves as an immune response for the injured individual, warding off parasites and … [Read more…]
FISH MATING STRATEGIES In honor of Valentines Day, please enjoy the first series of post for this blog post on fish mating strategies! Check back weekly for new additions to the “Fish-ionary.” Promiscuous: A mating system where both sexes have multiple partners during the breeding system. In fishes, this is the most common mating system. … [Read more…]