If you’ve ever eaten a fish fillet, you’ve probably had the ‘pleasure’ of picking out fish bones from your meal. While most fish are, indeed, bony (superclass: Osteichthyes), certain lineages of fish have cartilaginous skeletons, meaning that their skeletal structure is composed of cartilage, like a human ear or nose, rather than bone. Elasmobranchs (sharks, skates, … [Read more…]
Las comunidades locales puertorriqueñas se refieren al pes nativo postlarva, S. plumieri, como cetí. Las especies de peces de agua dulce puertorriqueña como “dajao,” “gauvina,” y “olivo,” (nombre común del cetí en su fase adulta) son anfidromas. La historia de vida de estos peces incluyen una fase de aqua dulce y marina. En particular, los … [Read more…]
Guest post: Logan Neu, University of Minnesota Twin Cities A creel survey (also known as an angler survey) is a type of in-person survey performed by resource managers where an interviewer asks an angler questions about their fishing experience including questions such as the duration of the trip, how many fish they caught, and if … [Read more…]
A culvert is essentially a tunnel to pass flowing water, typically a small stream, under a man-made structure, usually a road. Depending on the size, placement, and design of a culvert, the impacts to a stream channel vary. These impacts, in turn, can affect fish habitat and fish migration. Culverts are frequently barriers to fish … [Read more…]
Guest post by Emily Argo Countershading, originally described in the late 1800s, is when one side of an animal is dark and the other is light, serving as a form of camouflage. In fish, such as the Atlantic Bluefin Tuna (Thunnus thynnus) pictured, this typically means the ventral side (bottom) is light and the dorsal … [Read more…]
Chondrichthyes are a taxonomic class of cartilaginous fishes that encompass sharks and rays (elasmobranchs) and chimaera. Though there are exceptions, in general, Chondrichthyes have exposed gills, no swim bladder, internal fertilization, and placoid denticles. These characteristics differentiate them from the more evolutionarily derived branch of fishes, bony fish (Osteichthyes).
A catadromous fish hatches and spawns in salt water but spends most of its life in fresh water. Catadromous life cycles are much less common than anadromous life cycles. American and European Eels (Anguilla rostrate and A. anguilla, respectively) are among the more famous fish that utilize this unusual migration pattern. They have a highly … [Read more…]
The caudal peduncle is the tapered region behind the dorsal and anal fins where the caudal fin attaches to the body. The depth of the caudal peduncle, which is measured at its narrowest point, gives some indication of the power of a fish and the speed at which it can swim. For example, ambush predators, … [Read more…]
Ctenoid scales are scales with comb-like edge found in higher order teleost fishes, such as perch and sunfish. Cteni are the tiny teeth on the posterior margin of the scale. Similar to cycloid scales, they are overlapping which allows for greater flexibility in movement than other types of scales such as ganoid scales. The surface layer … [Read more…]
Cycloid scales are smooth-edged scales predominately found in lower order teleost fishes, such as salmon, carp and other soft fin rayed fish. Similar to ctenoid scales, they are overlapping which allow for greater flexibility in movement than other types of scales such as ganoid scales. The surface layer of the scale is comprised of calcium-based … [Read more…]