Food and Feeding Ecology of the Non-native Nile Tilapia Oreochromis niloticus (Linnaeus, 1758) in the River Yamuna, India

Autor: S. K. Chakraborty, S. C. S. Das, Tarkeshwar Kumar, Kalpana Srivastava, Paramita Banerjee Sawant, Amita Sharma, Absar Alam, Narinder Kumar Chadha, K. D. Joshi
Rok vydání: 2014
Předmět:
Zdroj: Proceedings of the National Academy of Sciences, India Section B: Biological Sciences. 85:167-174
ISSN: 2250-1746
0369-8211
DOI: 10.1007/s40011-014-0338-3
Popis: Nile tilapia Oreochromis niloticus is the dominant invasive species of the river Yamuna. Gut analysis showed that the majority of the food items ingested consisted of Chlorophyceae, Myxophyceae, Bacillariophyceae and detritus. Among the diatoms—Synedra spp. (80.75 %), Melosira spp. (73.5 %), Cyclotella spp. (73 %), Meridion spp. (71.75 %) and Nitzchia spp. (73.25 %), the green algae—Ankistrodesmus spp. (71.00 %), Coelastrum spp. (61.5 %), Scenedesmus spp.(52 %), Tribonema spp. (49.5 %), Protococcus spp. (58.5 %), Oocystis spp. (49.75 %) and Pediastrum spp. (49.5 %) and among blue green algae, Oscillatoria spp. (70.5 %), Anacystis spp. (61.5 %) and Phormidium spp. (46.5 %) showed high frequency of occurrence. The Gastrosomatic Index in males and females ranged from 0.23 to 0.93 and 0.25 to 1.1 respectively with no significant difference between males and females throughout the year (t test, p > 0.05). In addition to this, higher percentage of males and females showing low feeding intensity during all the months except in January indicted the species to be the poor feeder. However, the condition factor >1 suggested the species to be in good condition throughout the year in both males and females. Dominancy of detritus and pollution indicator genera Synedra spp., Anacystis spp., Ankistrodesmus spp., Melosira spp., Nitzchia spp., Oscillatoria spp., Phormidium spp. and Scenedesmus spp. suggested Nile tilapia to be the cleaner of the polluted river Yamuna.
Databáze: OpenAIRE
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