Effect of water temperature on egg incubation time and quality of newly hatched larvae of northern pike (Esox lucius L., 1758)

Abstract

Effect of water temperature on egg incubation time and quality of newly hatched larvae of northern pike (Esox lucius L., 1758) Summary This study examined the effect of temperature on egg incubation, survival of eggs during embryonic development and quality of newly hatched larvae of northern pike (Esox lucius L.) under laboratory conditions. Eggs of similar size (diameter 2.7 AE 0.16 mm and weight 6.11 AE 0.35 mg) from five females were incubated at 3, 6, 10, 14, and 18°C (groups A, B, C, D, and E, respectively). The lowest fertilization (FR) and hatching rates (HR) were observed in larvae incubated in group A, 44.6 AE 3.2% and 18.26 AE 2.25%, respectively. The highest FR and HR were found in group B (FR, 71.3 AE 4.3%; HR, 56.2 AE 3.21%) and C (FR, 65.6 AE 3.1%; HR, 65.5 AE 5.41%). Time of incubation period varied from 38 AE 0.33 days (120 AE 1.03°d) when 5% larvae were hatched to 46 AE 0.42 days (144 AE 1.31°d) when 95% larvae were hatched in group A and 2.5 AE 0.08 days (44.67 AE 1.42°d) when 5% larvae were hatched to 3.42 AE 0.06 days (61.11 AE 1.07°d) when 95% larvae were hatched in group E. Larvae from groups A, D, and E were characterized by the lowest values of variables such as resistance to osmotic stress after 90 min of exposure of saline solution (OS = 54 AE 3-76 AE 3%), frequency of normally developed larvae (FNL = 23.8 AE 4.14-87. 1 AE 2.42%), and yolk sac volume (YsV = 3.41 AE 0.44-3.89 AE 0.45 ll 3 ). The highest quality larvae were recorded in groups B and C: OS = 92 AE 3% and 80 AE 4%, FNL = 89.7 AE 3.62% and 93.8 AE 3.17, YsV = 3.3 AE 0.66 ll 3 and 3.04 AE 0.42 ll 3 ). Fertilization and hatching rates and quality of larvae showed optimal temperature for successful egg incubation and production of high quality larvae to be 6 to 10°C. Relationship of ontogenic rate to temperature showed development of the pike embryo to be hypothetically stopped at 3.3°C.U.S.

Embryonic and larval development of the northern pike: An emerging fish model system for evo‐devo research

“…Ten individuals were randomly selected twice a day from each cohort for developmental staging and inspection for developmental abnormalities, until hatching occurred in 80% of examined individuals. On the basis of these data, the average heat needed to reach each developmental stage was calculated and expressed as “day‐degrees,” i.e., the average temperature in degrees of Celsius above the pike's known lower developmental threshold (3.3 °C) per day (Bondarenko et al, ). To visualize the effect of different temperature regimes we fitted locally estimated scatterplot smoothing (loess; α = 0.75) curve to the measured data using loess function in R 3.3.2 (R Core Team, ).…”

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“…Sperm was collected according to Bondarenko et al (2015). In total, 400 μl of sperm was mixed with 5 g of eggs, and 20.6 ml of activation solution (100 g CO(NH 2 ) 2 and 25 g l -1 NaCl dissolved in 5 l hatchery water) was simultaneously added and mixed with eggs and sperm.…”

“…In total, 400 μl of sperm was mixed with 5 g of eggs, and 20.6 ml of activation solution (100 g CO(NH 2 ) 2 and 25 g l -1 NaCl dissolved in 5 l hatchery water) was simultaneously added and mixed with eggs and sperm. After fertilization and elimination of egg stickiness (Bondarenko et al, 2015), a sample of 200 eggs was collected from each batch. Three egg samples from each female were placed into separate transparent 2.5 l incubators (Svinger et al, 2013c) for incubation and determination of fertilization and hatching rate (Policar et al, 2010).…”

“…Northern pike Esox lucius L. is an important piscivorous fish in the freshwater ecosystems of northern hemisphere temperate zones (Hazman and Gökçek, 2014) and is also a popular food fish and in sport angling (Bondarenko et al, 2015). Northern pike have synchronous development of oocytes and they spawn annually in the spring at water temperatures between 5 and 12°C (Farrell et al, 1996).…”

“…The main drawbacks to this type of production are disparity in female maturation stages and a total reliance on environmental factors. These limitations reduce the possibilities for production of same-age larvae that are needed for successful subsequent culture (Bondarenko et al, 2015). A single 3 mg kg -1 injection of carp pituitary is the only confirmed method of inducing mass ovulation in mature females harvested from ponds or lakes (Billard and Marcel, 1980).…”