It was almost spawning time, and the big brookies probably gathered there because a hint of flow deceptively suggested the existence of a tributary in which they could find ideal spawning habitat.
22.
State dredging permits in many of the United States gold dredging areas specify a seasonal time period and area closures to avoid conflicts between dredgers and the spawning time of fish populations.
23.
Unlike other Southland water-supply reservoirs that often are in the phase of losing water when the warmwater species are moving shallow to spawn, Eastside will generally be coming up slowly during spawning time.
24.
The pygmy smelt coexists with the rainbow smelt " Osmerus mordax ", and is distinguished from it by slower growth, earlier maturation, shorter life span, later spawning time, and use of smaller food items.
25.
During the 19th and early 20th centuries trout cod were recognised by the scientific community as separate species, due to differing habitat preferences, morphological differences ( especially the much smaller size at sexual maturity ) and differing spawning times.
26.
Although the deal ignores scientific advice calling for a total ban on catches of some species, Fischler said the new long-term protective measures, such as keeping areas off-limit during spawning times and tougher monitoring of catches meant conservation considerations had been respected.
27.
If there is a distinct evolutionary advantage of retaining the oldest fish in the population, either because of higher fecundity or because of different spawning times, age-truncation could be ruinous to a population with highly episodic recruitment like rockfish ( Longhurst 2002 ).
28.
The principal measures against lampreys, short of catching and eating them ( Henry I of England died in 1135 after consuming some ), have included applying lampricides to larval habitats, trapping them at barriers and releasing sterilized males at spawning time in the spring.
29.
The fry continue to use on the sticky gland on their heads to attach themselves to pieces of vegetation etc,, for a short time . " Hepsetus cuvieri " lives in the more unpredictable seasonal swamp and has flexible spawning times because their bubblenests allow them to reproduce even when levels of dissolved oxygen are low, so they do not have a distinct breeding season.
