A histological study of gametogenesis in captive red snapperLutjanus campechanus

Abstract

Gametogenesis was monitored histologically in wild‐caught red snapper (Lutjanus campechanus, Poey) maintained in captivity under simulated natural photothermal conditions. Gonads were collected every 2–3 weeks (average n = 14) for histology during the pre‐spawning season (February to May, temperature increasing from 16°C to 24°C). Primary vitellogenic oocytes were first observed in one female when temperature reached 20°C. Subsequent samples revealed females in pre‐vitellogenesis or at early stages of vitellogenesis, although one female had tertiary vitellogenic (Vtg3) oocytes. The first histological signs of spermatogenesis were observed when temperature reached 17°C. Spermatozoa were observed in testicular lobules of all males sampled on 14 May (24°C) but little or no sperm was released during manual stripping. Ten males and 10 females were left in tanks and monitored for spawning. No egg release was observed during the monitoring period that encompassed the natural spawning season of wild red snapper. Ovarian biopsies taken during the late spawning season (16 July) revealed that four of eight sampled females had Vtg3 oocytes. Males were manually stripped but released no sperm. These results indicate that captive red snapper can complete gametogenesis in photothermal controlled systems. Additional research is needed to develop procedures that will achieve reliable maturation and spawning.

Advancements in hatchery production of red snapper Lutjanus campechanus: Exclusive use of small strain rotifers as initial prey for larval rearing

“…In many studies involving L. campechanus , major bottlenecks were reported during the first days of larval rearing related with the first feeding, and high mortalities were observed as a consequence after 8 DPH (Bardon‐ Albaret, 2014; Bardon‐Albaret et al, 2013; Bardon‐Albaret & Saillant, 2017; Ogle & Lotz, 2006; Saillant et al, 2013; Williams et al, 2004). Such issues were not observed in the present study.…”

“…The red snapper Lutjanus campechanus is one of the most economically important marine fish species in the Gulf of Mexico and South Atlantic coast of United States (Bardon‐Albaret & Saillant, 2017). Overfishing led to intensive management of the red snapper stock since 1990 (Bardon‐Albaret et al, 2013); and since 2018 the species is no longer considered overfished (NOAA, 2020). Nonetheless, fishery closures remain in place throughout most of their range.…”

“…Previous research conducted on red snapper focused on describing the early larval stages as well as spawning induction techniques for wild‐caught broodstock (Arnold et al, 1978; Bardon‐Albaret et al, 2013; Hastey et al, 2013; Papanikos et al, 2008; Rabalais et al, 1980; Saillant et al, 2013; Williams et al, 2004). While providing the baseline for hatchery technology development for this species, much of this work was constrained by difficulties in obtaining volitional spawning in captivity and high mortalities during the early developmental stages associated with first feeding of the larvae.…”