Generation time of zebrafish (Danio rerio) and medakas (Oryzias latipes) housed in the same aquaculture facility

Abstract

The zebrafish and the medaka are both important model organisms in biomedical research. Both species are frequently characterized as having a generation time of approximately 2-4 months, but the precise onset of sexual maturity and the variability of reproductive success with age have not been previously examined. The authors studied reproduction in replicate groups of wild-type zebrafish (strain AB) and medakas (strain Cab) that were maintained together in the same aquaculture system. Length, weight and survival of the fish were measured and recorded once per week. Reproductive success and viability of offspring were also evaluated. Both zebrafish and medakas began producing viable embryos within 60 d post-fertilization. These findings show that it is possible to successfully maintain populations of both species within the same research infrastructure without compromising reproductive success or embryo viability.

A Novel Method for Rearing Zebrafish by Using Freshwater Rotifers (Brachionus calyciflorus)

“…A male and a female AB fish were placed in a 1-L breeding tank with a spawn insert (Aqua Schwarz GmbH, Göttingen, Germany) on the evening before the embryos were required. Three sets of four AB fish pairs were set up in a 2-L hand-made breeding tank, which was previously described, 13 to obtain enough embryos for the rearing experiments (see next section). The next morning, fertilized embryos were selected and kept in 10-cm Petri dishes (50 embryos/dish) filled with 1/3 Ringer solution (39 mM NaCl, 0.97 mM KCl, 1.8 mM CaCl 2 , and 1.7 mM HEPES at pH 7.2) at 28.5°C.…”

“…Definitions of total length and standard length are the same as described in previous publications. 8,13 Measurement of the total and standard lengths of five larvae was performed using ImageJ software, and the means of both lengths were calculated. Results are depicted as means -SEM.…”

“…11 Saltwater rotifers (Brachionus plicatilis) were reported as a good source of nutrients for newly hatched larval fish. 12 Moreover, fish have reached sexual maturity *60 days postfertilization (dpf) 13 after consuming saltwater rotifers. Thus, provision of saltwater rotifers greatly improves zebrafish generation time and survival rate (*90%), 12,13 but several problems remain.…”

“…12 Moreover, fish have reached sexual maturity *60 days postfertilization (dpf) 13 after consuming saltwater rotifers. Thus, provision of saltwater rotifers greatly improves zebrafish generation time and survival rate (*90%), 12,13 but several problems remain. The main issue concerns the saltwater rotifer itself.…”

Non-stressful temperature effect on oxidative balance and life history traits in adults fish (Oryzias latipes)

“…Here, we used 76 individuals belonging to the CAB strain from Carolina Biological Supply Company (Burlington, NC, USA; from AMAGEN, Gif-sur-Yvette, France) and WatchFrog (Evry, France). Fish of this standard strain present differences in the colour of eyes and other tissues (Loosli et al, 2000;Furutani-Seiki and Wittbrodt, 2004;Sasado et al, 2010;Kinoshita et al, 2009), but can be used in ecophysiological studies because their development characteristics are similar to those of the wildtype (Sasado et al, 2010;Lawrence et al, 2012). They were studied from 4 months old (mature) to 8 months old [almost the end of life at 27°C (Shima and Mitani, 2004;Leaf et al, 2011)].…”