Analysing the diel feeding patterns and daily ration of Nile tilapia, Oreochromis niloticus (L.), in Laguna de Bay, Philippines

Cage cultured Nile tilapia, Oreochromis niloticus, were sampled at a commercial set-up on two occasions in 1995 in Laguna de Bay, Philippines, each time over a 24 h cycle. The stomach content weights were averaged for each subsample and analysed with the computer model MAXIMS. The model predicted that, in May, larger fish (mean total weight: 31.5 g) feeding on natural food alone fed continuously from dawn to dusk, ingesting 5.1 % body mass equivalent (% BME, wet weight basis) whereas smaller fish (mean total weight: 9.8 g) had two feeding periods per day, from sunrise to mid-morning and again from mid-afternoon until after sunset, ingesting 13.7 % BME. In August, fish were given supplemental feed once daily at 07:00 h. These fish (mean total weight: 81.7 g) fed intensely until supplemental feed ran out before mid-day, after which some ingestion of natural food took place later in the day. The fish ingested 5.8 % BME supplemental feed and 5.1 % BME natural food per 24 h. In May, most of the stomach contents consisted of the blue-green alga Anabaena spiroides, whereas in August, the natural food was made up principally of detritus.This study was carried out as part of the STD-3 project 'Laguna de Bay, Philippines: An ecosystem approach to sustainable management' funded by the European Union (Contract No. CT94-0334)

Wild and domesticated Moringa oleifera differ in taste, glucosinolate composition, and antioxidant potential, but not myrosinase activity or protein content

Taste drives consumption of foods. The tropical tree Moringa oleifera is grown worldwide as a protein-rich leafy vegetable and for the medicinal value of its phytochemicals, in particular its glucosinolates, which can lead to a pronounced harsh taste. All studies to date have examined only cultivated, domestic variants, meaning that potentially useful variation in wild type plants has been overlooked. We examine whether domesticated and wild type M. oleifera differ in myrosinase or glucosinolate levels, and whether these different levels impact taste in ways that could affect consumption. We assessed taste and measured levels of protein, glucosinolate, myrosinase content, and direct antioxidant activity of the leaves of 36 M. oleifera accessions grown in a common garden. Taste tests readily highlighted differences between wild type and domesticated M. oleifera. There were differences in direct antioxidant potential, but not in myrosinase activity or protein quantity. However, these two populations were readily separated based solely upon their proportions of the two predominant glucosinolates (glucomoringin and glucosoonjnain). This study demonstrates substantial variation in glucosinolate composition within M. oleifera. The domestication of M. oleifera appears to have involved increases in levels of glucomoringin and substantial reduction of glucosoonjnain, with marked changes in taste