The Indigenous Probiotic PH3-05 Enhances the Growth, Digestive Physiology, and Gut Microbiota of the Tropical Gar () Larvae.

Probiotics in aquaculture hold promise for enhancing fish health and growth. Due to their increased specificity and affinity for their host, indigenous probiotics may offer isolated and potentially amplified benefits. This study investigated the effects of PH3-05, previously isolated from adults of tropical gar (), on the growth, survival, digestive enzyme activity, intestinal morphology, expression of barrier and immune genes, and intestinal microbiota composition in the larvae of tropical gar.

Identification and expression analysis of transcripts involved in taurine biosynthesis during early ontogeny of tropical gar Atractosteus tropicus.

In fishes, the availability of taurine is regulated during ontogenetic development, where its endogenous synthesis capacity is species dependent. Thus, different pathways and involved enzymes have been described: pathway I (cysteine sulfinate-dependent pathway), cysteine dioxygenase type 1 (cdo1) and cysteine sulfinic acid decarboxylase (csad); pathway II (cysteic acid pathway), cdo1 and glutamic acid decarboxylase (gad); and pathway III (cysteamine pathway), 2-aminoethanethiol dioxygenase (ado); whereas taurine transporter (taut) is responsible for taurine entry into cells on the cell membrane and the mitochondria. This study determined if the tropical gar (Atractosteus tropicus), an ancient holostean fish model, has the molecular mechanism to synthesize taurine through the identification and analysis expression of transcripts coding for proteins involved in its biosynthesis and transportation, at different embryo-larvae stages and in different organs of juveniles (31 dah).