Food and feeding habits of wild guppy (Poecilia reticulata), in natural water bodies of Sri Jayewardenepura canal system, Sri Lanka

Abstract

Guppy (Poecilia reticulata) is a small freshwater fish belonging to the family Poeciliidae, first introduced to Sri Lanka in 1928 and used to control malaria mosquito vectors during1940-1950. The present study investigates the food and feeding habits of wild guppy. The six locations identified for sampling between January 2016 and December 2017 were: Attidiya, Bellanwila, Rattanapitiya, Nawala, near Parliament Grounds, and Jayewardenepura Hospital. Once a month, water and fish samples were collected from each sampling site and sent to the lab for analysis (n=216; n=2160). The researcher measured the Total Length (TL), Total Width (TW), and the weight of fish with an accuracy limit of 1mm and 0.1mg, respectively. Under the microscope, the food items in the dissected stomach were identified using the standard keys and counted using a Sedgewick-Rafter cell to calculate the percentages. Female fishes were larger than males, and the average mean of body length value was 24.56 ± 5.46 mm (range: 1535 mm) in females and 20.19 ± 2.75 mm (range: 15.0-24.5 mm) in males. Mean body weight of females and males were recorded as 0.174 ± 0.105 g (range: 0.026- 0.382 g) and 0.075 ± 0.021g (0.024- 0.11 g) respectively. Guppy has consumed most of the food items available in water (freshwater debris). Their feeds mainly consisted of freshwater debris (41%), phytoplankton (24 %), zooplankton (21 %), unidentified insect parts (12%), and adult mosquito parts (2%). The guppy is an omnivore, and in the wild, they feed on a combination of animal and plantbased meals.