this study was carried out to evaluate the chemical compoition of alosa caspia and results compared with clupeonella engrauliformis which is a common fish catch among clupeonella and clupeidae spp in caspian sea . results showed that the amount of fat, protein, ash and dry matter in alosa was higher than clupeonella. the fatty acid composition showed that the epa was very high in alosa that sho...

Predicting the success of a species' colonization into a novel environment is routinely considered to be predicated on niche-space similarity and vacancy, as well as propagule pressure. The role genomic variation plays in colonization success (and the interaction with environment) may be suggested, but has not rigorously been documented. To test an hypothesis that previously observed ecotype-sp...

Diadromous species are particularly vulnerable to climate change because they utilize both marine and freshwater habitat complete their life cycles. Dispersal plays an important role in restraining the distribution of plant animal species, is a key mechanism allow diadromous adapt changes suitability, but it often not included models that explore population trends under scenarios. The objective...

1 Department of Biological Sciences The University of Southern Mississippi 118 College Drive, #5018 Hattiesburg, Mississippi 39406-5018 2 Southern Research Station U.S. Forest Service U.S. Department of Agriculture 1000 Front Street Oxford, Mississippi 38655 3 Waterways Experiment Station EE-A Engineer Research and Development Center U.S. Army Corp of Engineers 3909 Halls Ferry Road Vicksburg, ...

—American shad Alosa sapidissima in semelparous and iteroparous populations along its native range are thought to have nearly equivalent lifetime reproductive output due to reciprocal latitudinal trends in fecundity and degree of repeat spawning. Geographic differences in reproductive patterns are believed to be linked to varying environmental conditions, and this fine tuning is considered stro...

Many species of odontocete cetaceans (toothed whales) use high-frequency clicks (60-170 kHz) to identify objects in their environment, including potential prey. Behavioral studies have shown that American shad, Alosa sapidissima, can detect ultrasonic signals similar to those of odontocetes that are potentially their predators. American shad also show strong escape behavior in response to ultra...