AN OBSERVATION ON INTRACAPSULAR AND POST-EMBRYONIC PHASES OF RIVER NERITE (Theodoxus fluviatilis)
Abstract
The river nerite (Theodoxus fluviatilis, Linnaeus, 1758) is one of the most common gastropod grazer species in Europe inland and brackish waters. Its feeding activity significantly impacts on periphyton which has a decisive role on the water parameters and the population dynamics. In the present study, reproductive outputs and larval phases of the river nerites were examined via field collected and laboratory cultivated samplings. The length of capsules laid by adults was between 0.7 and 1.1 mm. Viable embryos were detected first on the 33rd day post-spawning. After few development phases embryo reached a ready-to-hatch phase with completely developed foot and pigmented protoconch before hatching. There was never more than one embryo per capsule. The earliest hatching was observed on the 53rd day of spawning. But most of the embryos did not hatch even they were fully developed. The shell length of the hatchlings was about 0.8 and the width was 0.6 mm. It was estimated that the length of a newly hatched crawling juvenile can be about 1/7 of the length of an adult.
Keywords
References
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Details
Primary Language
English
Subjects
Hydrobiology
Journal Section
Research Article
Authors
Mehmet Güler
*
Adnan Menderes University, Faculty of Agriculture, Department of Aquaculture and Fisheries, Aydın, Turkey
0000-0001-8257-1138
Türkiye
Deniz Çoban
Adnan Menderes University, Faculty of Agriculture, Department of Aquaculture and Fisheries, Aydın, Turkey
0000-0001-7058-3123
Birsen Kırım
This is me
Adnan Menderes University, Faculty of Agriculture, Department of Aquaculture and Fisheries, Aydın, Turkey
0000-0003-3292-1368
Publication Date
January 1, 2018
Submission Date
August 14, 2017
Acceptance Date
December 24, 2017
Published in Issue
Year 1970 Volume: 4 Number: 1