Observations of growth changes during the embryonic‐larval‐transition of pikeperch (Sander lucioperca) under near‐natural conditions

Abstract

Sander lucioperca is an organism of growing importance for the aquaculture industry.Nonetheless, the rearing of S. lucioperca larvae is proving to be a difficult task as it is facing a high mortality rate during hatching and the change to exogenous feeding. To gain insight into growth patterns during this period, the authors analysed pikeperch embryos and larvae from 9 days before hatching to 17 days after hatch. Hereby they were able to describe a natural development by using close to natural conditions based on using a direct flow-through supply of lake fresh water on specimens from a local wild population. The results show that between the early embryonic stages a steady growth was visible. Nonetheless, in between hatching and the start of exogenous feeding, a phase of growth stagnation took place. In the following larval stages, an increased growth with large size variations between individual specimens appeared. Both factors are conspicuous as they can indicate a starting point for cannibalism. With this analysis, the authors can provide a fundament to support the upcoming research on S. lucioperca and aid to optimize size-sorting procedures for a higher survival of pikeperch stock in aquaculture.

Does Size Matter? Small and Large Larvae of Pikeperch (Sander lucioperca) in a Comparative Gene Expression Analysis

“…Similarly, a study with a focus on skeletal development demonstrated an intermediate reduction in size increase for individual pikeperch reared in environments with constant temperatures [10]. As a result of these studies, a distinct early larval growth phase with a low to no size increase can be differentiated from a later larval growth phase with increasing size variants [9,10]. Based on the occurrence of characteristic ontogenetic events, these groups can be attributed to the larval stages L1 to L2 (early larval group) as well as L3 to L6 (late larval group) described by Pe ňáz [11].…”

“…The growth of pikeperch larvae does not occur steadily during development. A previous study described different phases of growth occurring during the larval development of pikeperch reared in a semi-natural environment [9]. Similarly, a study with a focus on skeletal development demonstrated an intermediate reduction in size increase for individual pikeperch reared in environments with constant temperatures [10].…”

“…Pikeperch larvae were obtained from a fishery at Lake Hohen Sprenz in Mecklenburg-Vorpommern, Germany, that applies semi-controlled pikeperch reproduction (compare with [9,14]). From a local population of breeders of three females and five males, a mixed clutch nest from one fertilisation date was sampled.…”

“…Due to the natural temperature variances and different sampling days, the calculation of dd is used to determine the developmental age of the poikilothermic organisms. In accordance with developmental [11] as well as described growth differences during larval development [9], the specimens were separated into an early and late larval group. In total, we collected six larval age stages (early larval: 16 dpf/227 dd, 18 dpf/256 dd, 21 dpf/306 dd; late larval: 31 dpf/512 dd, 35 dpf/600 dd, 38 dpf/666 dd).…”

“…accordance with developmental [11] as well as described growth differences during larval development [9], the specimens were separated into an early and late larval group. In total, we collected six larval age stages (early larval: 16 dpf/227 dd, 18 dpf/256 dd, 21 dpf/306 dd; late larval: 31 dpf/512 dd, 35 dpf/600 dd, 38 dpf/666 dd).…”