2024 : 6 : 21
Hamed Ghobari

Hamed Ghobari

Academic rank: Associate Professor
Education: PhD.
ScopusId: 56801091100
Faculty: Faculty of Agriculture
Phone: 09183715818


The optimum water temperature and degree days for the Chironomus riparius (Meigen, 1804) growth
Chironomus riparius, optimum, temperature, degree days, biometric, daily growth
Researchers Sorour Hemmati ، Habibiollah Mohammadi ، Edris Ghaderi ، Hamed Ghobari ، Armin Namayandeh


Chironomus (Chironomus) riparius Meigen, 1804 colonized the water refinery of Sanandaj, Kurdistan, Iran, and caused nuisance and disturbance to its function. Researchers from the Kurdistan University undertook the task of controlling and eventually eradicating this species from the refinery between 2019 and 2021. As part of this effort, larvae were transferred and reared in the laboratory to mimic some in situ environmental variables to understand their niche requirements. As an offshoot of these laboratory efforts, the importance of the larva as a food source for aquaculture fish has been identified. Specifically stocking and mass rearing of C. riparius can be improved by determining optimum environmental conditions such as temperature and degree days. Larvae reared from eggs were transferred to 3 ml microplates and reared in incubators at temperatures 10, 15, 20, 25, and 30 Celsius. Daily light was mimicked using LED lamps with 14 hours of sunlight and 10 hours of darkness. Larvae were fed every other day, once daily, using a fermented mixture (1µL), and their growth was monitored to pupation and emergence. At the end of each trial experiment, biometric measurements of total length, wet weight, head length, and width were obtained for larvae, pupae, and adults. A model of growth rate as a function of degree days was developed using the assumption that growth rate is a linear function of temperature. The optimum temperature for larval C. riparius we obtained based on these experiments was 18.17 ± 0.03 ℃. We calculated the degree days for larval instars 1 to 4 and pupae at this temperature as: 106 ± 132, 248 ± 86, 397 ± 170, 528 ± 153, and 498 ± 235. Using these conditions, the rearing and cultivation of C. riparius for the purposes of aquaculture can be maximized.