Female flowers of tropical seagrass Syringodium isoetifolium (Alismatales: Cymodoceaceae) in an ex-situ aquarium

Abstract

Flowering is an important component of seagrass life cycle, but so far the flowering habit of seagrasses in the tropics remains largely understudied and/or under-reported. To date, only four out of the 12 seagrass species found in Singapore have limited phenological information described. A seagrass species, Syringodium isoetifolium, was observed to have flowered in an ex-situ aquarium. Only female flowers were produced and they lasted for ~five weeks before senescence. Flowering in Syringodium isoetifolium is postulated to be triggered by lowered temperatures in literature; however, that signal was absent in the environment of the ex-situ aquarium, which was monitored for temperature and nutrient levels in the prior nine months. Documentation of flowering habits of seagrasses grown in aquaria can provide useful information for field monitoring and conservation efforts for seagrass habitats.