The essential events in larviculture are not only the period of these susceptible ontogenetic stages, but also a diversity of vital physical appearances such as the hatching size, onset of feeding, and the efficacy of yolk utilization (Koumoundouros et al. 2001; Polo et al. 1991).
Hatching size ranges from 7 to 11 mm total length (TL; [12], [13]), with Hudson River larvae ranging in size from 15 to 18 mm TL at 10 to 15 days of age [14].
Incubation time, hatching success, incidence of body deformities, hatching size, and weight were also within the limits of healthy developed hatchlings.
Furthermore, elevated testosterone concentration inside the eggs may increase the yolk absorption efficiency (i.e. decreases the consumption rate of the yolk), but does not affect the hatching size of the offspring [ 39].
For the normally distributed variables of time eggs were alive (days), hatching timing (days), developmental stage at hatching, and size at hatching (mm), we used a generalized linear mixed model with two-way anovas and Type III sums of squares in PROC GLIMMIX in SAS®, with the fixed-effect factors of salt treatment, individual female, and their interaction.
Mechanisms reducing fitness in captivity and in the offspring of captive-wild matings are likely multifaceted, affecting behavior, swimming performance, imprinting, stress responses, growth, run-timing, developmental stability, developmental time to hatch, embryo size, maternal reproductive investment, body morphology and age-at-maturity, all of which may be linked to fitness.
And because salmon always return to the same stream or lake where they hatched, the size of these individual populations can be monitored fairly easily.
To provide a more informative analysis of elasticity, we decomposed the fecundity terms (HYSY and HYASY) into the primary rates that influence the number of young hatched; clutch size, nest success and the probability of re-nesting after failure.
Variation among families in (a) egg survival, (b) time to hatching (c) stage at hatching and (d) size (length) at hatching at different treatments, reporting the mean, minimum and maximum values (mean ± SE) for families for each treatment.
The interfamily variation in (A) percentage of eggs survived, (B) time eggs survived (days), (C) time to hatching (days), (D) developmental stage at hatching, and (E) size (length) at hatching (mm) for the offspring of 16 different female newts raised in Control solution.
