1 THE PURPOSE, COSTS AND BENEFITS OF FISH
... species were reduced by overfishing in the first half of this century (Jackson 1971). This decline led to a suggestion to introduce other fish species into the lakes so as to improve the fishery. ...
... species were reduced by overfishing in the first half of this century (Jackson 1971). This decline led to a suggestion to introduce other fish species into the lakes so as to improve the fishery. ...
eprint_1_17594_235
... can become infected (the environmental survival form of the organism) with their feces. The active (trophozoite) stage exists only in the host and in fresh feces; cysts survive outside the host in water and soils and on foods, especially under moist conditions on the latter. When swallowed they caus ...
... can become infected (the environmental survival form of the organism) with their feces. The active (trophozoite) stage exists only in the host and in fresh feces; cysts survive outside the host in water and soils and on foods, especially under moist conditions on the latter. When swallowed they caus ...
Darwin`s dream : the evolution of African cichlids
... different lakes. The adaptations moreover appeared in parallel in each type of habitat. This discovery suggests that, in each lake, the rocky and pelagic habitats were colonized independently of each other by benthic ancestors. Therefore these fish did not undergo any evolutionary transition between ...
... different lakes. The adaptations moreover appeared in parallel in each type of habitat. This discovery suggests that, in each lake, the rocky and pelagic habitats were colonized independently of each other by benthic ancestors. Therefore these fish did not undergo any evolutionary transition between ...
Wildlife Resources Division - Georgia Public Broadcasting
... the forest where small trees and shrubs grow. (wild turkey) migrate/migratory: in wildlife usage, birds or other animals, which make annual migrations; i.e., travel distances in seasonal movements. Migrations may be great, or very short, depending on the species. (loggerhead sea turtle) migratory bi ...
... the forest where small trees and shrubs grow. (wild turkey) migrate/migratory: in wildlife usage, birds or other animals, which make annual migrations; i.e., travel distances in seasonal movements. Migrations may be great, or very short, depending on the species. (loggerhead sea turtle) migratory bi ...
the impacts of introduced freshwater fishes in the
... negative impacts of invasive fishes. Most of the invasive fishes have emanated from fishes introduced for the ornamental fish industry that have escaped or intentionally introduced into the wild and have become established. The list of 60 fishes reported in this study is by no means complete. The li ...
... negative impacts of invasive fishes. Most of the invasive fishes have emanated from fishes introduced for the ornamental fish industry that have escaped or intentionally introduced into the wild and have become established. The list of 60 fishes reported in this study is by no means complete. The li ...
Télécharger
... times (0-37 times was range of effects) as fast as non-transgenics (Devlin et al., 1994). Private industry is promoting transgenic fish and testing transgenic Atlantic salmon that grow 400% faster than normal (during first year) at an inland aquaculture facility in Scotland (Elliot Entis,N F Protein ...
... times (0-37 times was range of effects) as fast as non-transgenics (Devlin et al., 1994). Private industry is promoting transgenic fish and testing transgenic Atlantic salmon that grow 400% faster than normal (during first year) at an inland aquaculture facility in Scotland (Elliot Entis,N F Protein ...
Ecological Impacts of Non-native Freshwater Fishes (Cucherousset
... demonstrated that the presence of rainbow trout with Atlantic salmon led to a convergence in brain gene transcriptions between dominant and subordinate individuals of Atlantic salmon. In other words, an introduced competitor caused the suppression of gene differences between dominant and subordinate ...
... demonstrated that the presence of rainbow trout with Atlantic salmon led to a convergence in brain gene transcriptions between dominant and subordinate individuals of Atlantic salmon. In other words, an introduced competitor caused the suppression of gene differences between dominant and subordinate ...
Cowlitz Fall Chinook - Northwest Power and Conservation Council
... A number of factors are known to affect the likelihood and severity of such interactions, among them the abundance of the hatchery population relative to other populations; the time, size and life stage at which hatchery fish are released; and the quantity and quality of habitat available to the co- ...
... A number of factors are known to affect the likelihood and severity of such interactions, among them the abundance of the hatchery population relative to other populations; the time, size and life stage at which hatchery fish are released; and the quantity and quality of habitat available to the co- ...
Male-biased predation of a cave fish by a giant water bug
... measurements). H2S measurements were conducted photometrically in the laboratory according to Cline (1969) and oxygen was determined using a Hydrolab Multiprobe 4A. Single fish were introduced into a clear plastic bottle with 300 ml of water. After a 5-min acclimatization period, we measured the tim ...
... measurements). H2S measurements were conducted photometrically in the laboratory according to Cline (1969) and oxygen was determined using a Hydrolab Multiprobe 4A. Single fish were introduced into a clear plastic bottle with 300 ml of water. After a 5-min acclimatization period, we measured the tim ...
fish ecology - WordPress.com
... commensalisms, parasitism (carnivous fishes e.g. shark, claridea are normally found with fish in their stomachs) and population density. In competition when two individual compete, one is forced to migrate, or due to forces of evolution adapt to new way of life. Competition could be for spawning sit ...
... commensalisms, parasitism (carnivous fishes e.g. shark, claridea are normally found with fish in their stomachs) and population density. In competition when two individual compete, one is forced to migrate, or due to forces of evolution adapt to new way of life. Competition could be for spawning sit ...
Scarus guacamaia (Rainbow Parrotfish)
... parrotfish population was at peak as during this period, mangroves and coral reefs were still intact. It was found that in areas that were protected, the populations of these fish were significantly higher than in those that had minimal safeguard against overfishing. An estimate of this decline may ...
... parrotfish population was at peak as during this period, mangroves and coral reefs were still intact. It was found that in areas that were protected, the populations of these fish were significantly higher than in those that had minimal safeguard against overfishing. An estimate of this decline may ...
Slide 1
... • Stomatopod males feed only the three nights of the month when goatfish school over their burrows, which are always directly under these fish aggregation sites, both on Molokai, and also in Moorea, Tahiti, where they have been studied for a long time by UCB. • Feeding on a lunar cycle requires at m ...
... • Stomatopod males feed only the three nights of the month when goatfish school over their burrows, which are always directly under these fish aggregation sites, both on Molokai, and also in Moorea, Tahiti, where they have been studied for a long time by UCB. • Feeding on a lunar cycle requires at m ...
Climate change direct effects on Antarctic fish and indirect effects on
... the spatial range in which marine fish can survive. Fish living in the Antarctic environment are exposed to a relatively stable environment temperature and are specialised to live in the cold. There are multiple studies confirming that there is a change in spatial ranges of marine fish with warmer t ...
... the spatial range in which marine fish can survive. Fish living in the Antarctic environment are exposed to a relatively stable environment temperature and are specialised to live in the cold. There are multiple studies confirming that there is a change in spatial ranges of marine fish with warmer t ...
Oceanic pelagic prey of benthopelagic fish in the benthic boundary
... quently, scavenging of these pelagic species may have given rise to their occurrence at these excessive depths. Pelagic species are eaten by benthopelagic fish at depths corresponding to their daytime vertical distribution in the oceanic water column, or, in the case of a few species, at greater dep ...
... quently, scavenging of these pelagic species may have given rise to their occurrence at these excessive depths. Pelagic species are eaten by benthopelagic fish at depths corresponding to their daytime vertical distribution in the oceanic water column, or, in the case of a few species, at greater dep ...
Effects of stocking-up freshwater food webs
... structure in freshwater systems globally. Many fish introductions into freshwater systems were intended to create recreational fisheries, whereas only a few targeted the conservation of threatened species [1]. Largemouth bass Micropterus salmoides, smallmouth bass Micropterus dolomieu, rainbow trout ...
... structure in freshwater systems globally. Many fish introductions into freshwater systems were intended to create recreational fisheries, whereas only a few targeted the conservation of threatened species [1]. Largemouth bass Micropterus salmoides, smallmouth bass Micropterus dolomieu, rainbow trout ...
Myxobolus cerebralis
Myxobolus cerebralis is a myxosporean parasite of salmonids (salmon, trout, and their allies) that causes whirling disease in farmed salmon and trout and also in wild fish populations. It was first described in rainbow trout in Germany a century ago, but its range has spread and it has appeared in most of Europe (including Russia), the United States, South Africa and other countries. In the 1980s, M. cerebralis was found to require a tubificid oligochaete (a kind of segmented worm) to complete its life cycle. The parasite infects its hosts with its cells after piercing them with polar filaments ejected from nematocyst-like capsules.Whirling disease afflicts juvenile fish (fingerlings and fry) and causes skeletal deformation and neurological damage. Fish ""whirl"" forward in an awkward, corkscrew-like pattern instead of swimming normally, find feeding difficult, and are more vulnerable to predators. The mortality rate is high for fingerlings, up to 90% of infected populations, and those that do survive are deformed by the parasites residing in their cartilage and bone. They act as a reservoir for the parasite, which is released into water following the fish's death. M. cerebralis is one of the most economically important myxozoans in fish, as well as one of the most pathogenic. It was the first myxosporean whose pathology and symptoms were described scientifically. The parasite is not transmissible to humans.