Protracted volitional spawning of pinfish Lagodon rhomboides and changes in egg quality and fatty‐acid composition throughout the spawning season

Abstract

Spawning performance of pinfish Lagodon rhomboides without use of hormonal aids was monitored over an extended season. Nearly three million eggs were obtained from 75 spawns collected over a 90-day consecutive period from a single population of four brood fish (1M:1F). A mean ± s.d. batch fecundity of 30·27 ± 22·64 eggs g female was estimated with 98·0 ± 0·06% of the batch composed of floating eggs which were 1·04 ± 0·04 mm in diameter and 85·71 ± 27·59% fertile. Floating eggs successfully hatched 54·65 ± 29·13% of the time which yielded larvae that were 2·59 ± 0·24 mm in length. Fatty acids within floating eggs were largely represented by polyunsaturated fatty acids (45·30 ± 2·14% of total fatty acids) of which linoleic acid [(c18:2n-6cis) 3·49 ± 1·69% trifluoroacetic acid (TFA)] and docosahexaenoic acid (DHA) [(c22:6n-3) 28·47 ± 1·48% TFA] represented the majority of fatty acids for n-6 and n-3 polyunsaturated fatty acids, respectively. The strongest correlations between fatty acids and hatching success and larval survival to first feeding were observed for the DHA:EPA (eicosapentaenoic acid; c20:5n-3) ratio and total n-6 polyunsaturated fatty-acids levels, respectively. These data demonstrate potential for producers to rely on natural spawns for extensive egg production and provide a baseline for future development of natural spawning protocols of captive L. rhomboides.

Efficacy of varying doses of cGnRH IIa on spawning performance of Pinfish and Pigfish

“…One of the most well‐known parameters correlated with egg and larval viability are the compartmentalized nutrient content of the eggs themselves. Strong relationships with poly‐unsaturated fatty acids within eggs with egg and larval viability have been reported in numerous species including other sparids (Fernandez‐Palacios et al., 1995; Harel, Tandler, & Kissil, 1994; Zakeri et al., 2011) and even suggested for pinfish (Broach, Ohs, & Breen, 2017) and pigfish (Broach, 2014). Given the ability of some marine broodfish with asynchronous batch spawning life‐history traits to adjust nutrient stores within eggs to closely match those of exogenous sources within a few weeks of diet alterations (Fernandez‐Palacios et al., 1995), reductions in spawn quality from potential changes caused in egg and oil droplet sizes after hormone administration might be counteracted by better formulated broodfish diets.…”

“…even suggested for pinfish (Broach, Ohs, & Breen, 2017) and pigfish (Broach, 2014). Given the ability of some marine broodfish with asynchronous batch spawning life-history traits to adjust nutrient stores within eggs to closely match those of exogenous sources within a few weeks of diet alterations (Fernandez-Palacios et al, 1995), reductions in spawn quality from potential changes caused in egg and oil droplet sizes after hormone administration might be counteracted by better formulated broodfish diets.…”

Fate or independency: is batch-specific larval performance determined by egg traits? A case study in farmed pikeperch (Sander lucioperca)

“…For example, the growth intercept of the SL was positively correlated with 15:0 and negatively correlated with 16:1n7. It is documented that an excess of specific FA can exert negative effects during early ontogeny (Fernández-Palacios et al 1995;Broach et al 2017;Schaefer et al 2018a). Yet, it is not clear which underlying patterns may explain for these observed counteracting effects.…”