Abstract Actinopterygians (ray-finned fishes) are the most diversified group of vertebrates and characterized by a variety protective structures covering their integument, evolution which has intrigued biologists for decades. Paleontological records showed that first mineralized vertebrate skeleton was composed dermal bony plates body, including odontogenic skeletogenic components. Later in evo...

The phylogenetic aEnity of lungfishes has been disputed since their discovery, and they have variously been considered the sister group of actinistians, the sister group of amphibians, or equally related to actinopterygians and crossopterygians. Previous discussions of these hypotheses have considered neural characters, but there has been no general survey of the nervous systems of sarcopterygi...

Archived blood smears from 32 of 113 fishes in 18 families and 12 orders, trawled from deep North Atlantic waters off the Cape Verde Islands in 1999 and over the Porcupine Seabight in 2001 were found to harbour haematozoans. These included four species of haemogregarines (Adeleorina, Haemogregarinidae) and a species of trypanosome (Trypanosomatina, Trypanosomatidae) located in Porcupine Seabigh...

ABSTI~.CT Using a specific fluorimetric and biological method, the occurrence and distribution of histamine was investigated in man, various mammals, birds, reptiles, amphibians, bony and cartilaginous fishes, lancelets, tunicates, echinoderms, molluscs, and crustaceans. The anune was identified by. the fluorescence spectrum, by specific antihistaminics in the bioassay, by the comparison of the...

Active learning and increased motivation to learn are common benefits of time spent in laboratory during a science course. Hands-on learning is an important aspect of the laboratory experience and increases comprehension of material learned during the lecture portion of college science courses. When the content of a course is extensive, such as that often found in biology courses, students may ...

By KEN WOLF S TUDIES ON BLOOD of freshwater bony fishes indicated that the coagulation reaction was similar to that of mammalian blood. A notable difference was reported for the rapidity with which fish blood coagulated. The process was reported to be swift; clotting times ranged from 10 seconds to about 1 mintite, with the mean being about 30 seconds.14 Convincing explanations for the rapid cl...

abstract different factors such as the quality of ova and sperm are involved in propagation process. mobility percentage, ph, mobility duration, compaction and osmolarity of sperm which affect the quality of sperm were tested in this research. this study was carried out in april 2011 in shahid ansari bony fishes propagation and rearing center. according to the results, mean and standard deviati...

The symmetrical, flexible teleost fish 'tail' has been a prime example of recapitulation - evolutionary change (phylogeny) mirrored in development (ontogeny). Paleozoic ray-finned fishes (Actinopterygii), relatives of teleosts, exhibited ancestral scale-covered tails curved over their caudal fins. For over 150 years, this arrangement was thought to be retained in teleost larva and overgrown, mi...

Boxfishes (Teleostei: Ostraciidae) are rigid-body, multi-propulsor swimmers that exhibit unusually small amplitude recoil movements during rectilinear locomotion. Mechanisms producing the smooth swimming trajectories of these fishes are unknown, however. Therefore, we have studied the roles the bony carapaces of these fishes play in generating this dynamic stability. Features of the carapaces o...