The rotifer fauna of peat-swamps in southern Thailand

Different taxa have had different degrees of success in invading and proliferating in the deep sea. The reasons for these differences are not well known, and exemplars need to be studied to provide insight as to factors that lead to success in the deep sea. Because the abundance of the deep-sea fauna taken as a whole declines with depth, the absolute abundance of a taxon is not an appropriate metric of its success. Rather, a taxon whose abundance declines as rapidly as or less rapidly than the general trend should be considered successful. In this paper, I used the macrofauna to define the general trend of abundance change with depth. When I compared the trend of abundance of harpacticoids to that for macrofauna, I found that harpacticoid abundance decreased less rapidly. Thus, harpacticoids are unusually successful in the deep sea. The reasons for their success are unknown, but I discuss three possible explanations.     

Effects of using cyanobacteria and fertilizer on growth and yield of rice,Pathum Thani I: a pot experiment

The effects of cyanobacteria and chemical fertilizer on growths and yields of rice (Oryza sativa L.) cv. Pathum Thani 1 were studied in pot trials. Nine treatments were set up without cyanobacteria and fertilizer (control), inoculated with cyanobacteria Nostoc carneum TUBT04 (T1), inoculated with Nostoc commune TUBT05 (T2), and inoculated with combination of N. carneum TUBT04 and N. commune TUBT05 (T3), full dose of recommended use of fertilizer (T4), half dose of recommended use of the fertilizer (T5), half dose of fertilizer combined with N. carneum TUBT04 (T6), half dose of fertilizer combined with N. commune TUBT05 (T7), and half dose of fertilizer combined with N. carneum TUBT04 plus N. commune TUBT05 (T8). Each treatment divides into five replications. Growth parameters including length and fresh and dry weights of shoot and root were measured in the seedlings. The number of spikes per plant and the amount and weight of rice grains per spike were measured after harvesting. The supplement with cyanobacteria promoted rice seedling growth and yield compared to the control treatment. Inoculation with cyanobacteria showed significant increase in root length (p = 0.41). In addition, the combined biofertilizer with a half of the recommended dose of chemical fertilizer significantly enhanced rice production including total number and weight of grain per spike and a total weight of 100 grains (p < 0.001). Therefore, using a half dose of chemical fertilizer with cyanobacteria is suggested to decrease rice production cost of farmers without any effects on rice quantity and quality.     

Rotifera from Peat-Swamps in Phuket Province,Thailand, with the Description of a New Colurella Bory de St. Vincent

The rotifer fauna of three peat-swamps in Phuket province, southern Thailand was investigated. A total of 77 species is identified, 12 of which are new to Thailand. A new species, Colurella sanoamuangae n. sp., is described. The zoogeography of the registered species is discussed.     

Fire and recovery of resting egg bank: an experimental study in paddy fields in Pathum Thani province,Thailand

The effects of straw burning, exposure conditions and exposure durations on the diversity of zooplankton resting eggs were examined by hatching resting eggs in sediment collected from rice fields in Pathum Thani province, Thailand. Well-mixed surface sediment samples from with- and without straw burning paddies were stored under three conditions, (4°C and darkness; 28–40°C and darkness; and 28–40°C and light), for different periods of time (0, 2, 4, 6, 8, 10 and 12 months). Thirty zooplankton species were identified from hatching experiments. Of these, 25 species were Rotifera, 3 were Cladocera, 1 was Ostracoda and 1 was Copepoda. Repeated Measurement analysis showed that straw burning significantly decreased the number of zooplankton species, the zooplankton abundance and zooplankton diversity (P = 0.000, 0.019 and 0.004, respectively). A significant effect of storage conditions on the number of species was also present (P = 0.016), whereas zooplankton abundance and zooplankton diversity were not affected (P = 0.583 and 0.180). In addition, exposure time had an effect on number of zooplankton species and diversity (P = 0.001 and 0.033) but not on zooplankton abundance (P = 0.676). The traditional practice of residue burning post harvest therefore has a substantially negative effect on zooplankton biodiversity.     

Restoration of Tropical Peat Swamp Rotifer Communities after Perturbation: an Experimental Study of Recovery of Rotifers from the Resting Egg Bank

In order to assess the recovery potential of tropical freshwater communities after disturbance, we performed an experimental study on the effects of exposure conditions and durations of storage on hatching of rotifer resting eggs in sediment. Well-mixed surface sediment samples from Mai Khao peat swamp on Phuket Island, Thailand, were stored under three conditions (cold –4 °C & dark: CD; ambient –32–42 °C & dark: AD; and ambient & daylight conditions: AL), for different periods of time (1, 2, 4, 6, 12, 18 and 24 months).The number of species hatching from the sediment was significantly affected by treatment for both short- (1–6 months) and long-term (6–20 months) exposure. Significant effects of short- and long-term exposure within treatments were also present. Both factors interacted significantly. Regarding numbers of specimens hatching, no short-term effects of differences in treatment condition were found, but increasing the duration did have an effect. Significant effects of treatment occurred after 6 months, in addition to prolonged effects of duration. Again, both factors interacted significantly. These experiments indicate that exposure time has a strong impact on the viability of resting eggs, whereas, an effect of exposure condition appears only after 6 months. So, recovery of rotifer communities from resident sediment egg banks in disturbed peat swamps can only be effectively attained when restoration occurs within a relatively short period after perturbation.     

Development of a fed-batch fermentation with stepwise aeration to enhance docosahexaenoic acid and carotenoid content in Aurantiochytrium sp. FIKU018

Journal of Applied Phycology - Aurantiochytrium&nbsp;has been recommended as an alternative source for docosahexaenoic acid (DHA) since it accumulates DHA more than 50% of the polyunsaturated...