Early hatchery protocols for tetrasporogenesis of the antimethanogenic seaweed Asparagopsis armata

Abstract The red alga Asparagopsis armata is an emerging aquaculture-target species due to its application as antimethanogenic feed ingredient in ruminants, yet information on A. reproduction and cultivation currently lacking. We therefore quantified the effects of temperature, irradiance, nutrients, photoperiod, addition plant growth regulators (PGRs; indole-3-acetic acid, abscisic 1-aminocyclopropane-1-carboxylic acid) tetrasporogenesis domesticated that had been maintained under controlled conditions (18 °C, 12 h light:12 dark photoperiod) for 18 months prior experimentation. Tetrasporogenesis was only induced at 5 15 µmol photons m −2 s −1 8 light:16 photoperiod with 3.5 mg nitrogen L tetraspore release 28-fold greater °C compared after 28 days exposure. After 29 days, germination rate both declined. All PGR treatments prevented tetrasporogenesis. This study first provide detail framework necessary enable hatchery development. conclude most likely response a significant reduction rather than result replicating seasonal environmental conditions, temperature played key role determining reproductive output. With overall higher consistent > 90%, we recommend exposing tetrasporophyte biomass L:16 D up obtain reliable supply tetraspores seeding onto ropes transfer phase.