Reproductive characteristics and variations in the biochemical composition ofNeptunea arthritica cumingii crosse through embryonic development

Abstract

The copulation, egg laying, embryonic development and changes in amino acids and fatty acids in Neptunea arthritica cumingii during embryogenesis were studied to understand the embryo development process and nutritional requirements in the early life phase. The results showed that N. arthritica cumingii has direct development within the egg capsule and the development of embryos was classified into five stages: cleavage, egg swallowing, protoconch forming, shell development and juvenile. Embryos develop through the provision of nurse eggs as an extra-embryonic source of nutrition. As development continued, the body of the embryo began to coil. After about 70-80 days, young N.arthritica cumingii started to emerge through a hole underneath the capsule. Biochemical results showed that the total amount of amino acids showed a decreasing trend as embryonic development progressed. The content of all nine essential amino acids decreased significantly from the egg-swallowing stage to the post-larva stage (p < .05). Concentrations of five of the seven nonessential amino acids also showed a decreasing trend from the egg-swallowing stage to the post-larva stage; the exceptions were Ala and Gly. Gly is the only amino acid that consistently increased in concentration during the development process. Most fatty acids increased after the eggs hatched, except for C20:1, C20:2, C22:5 and C22:6 (docosahexaenoic acid, DHA). The data in this study may provide a starting point for the formulation of well-balanced early-stage larval diets, although N.arthritica cumingii is still in the exploration stage.

Ontogenetic Changes During Development of the Whelk Neptunea cumingii Determined Using a Geometric Morphometric Method

“…This carnivorous gastropod undergoes creeping metamorphosis and primarily preys on bivalves, particularly the horse mussel Modiolus 3 . Hao et al, (2020) divided the embryonic development process of N. cumingii into ve stages based on oocyst and egg characteristics, highlighting its direct development within the oocyst. Nutrients in the oocyst provide nutritional support for developing embryos 4 .…”

Development and characterization of the microsatellite markers for the Neptune whelk, Neptunea cumingii

“…With adult whelk mainly in gravel and sand bottom, the bottom trawlers have been widely used to catch N. cumingii, resulting in a sharp decrease and threatened status of wild resources [3]. Consequently, to relieve stress of over shing and protect the wild resources, research on N. cumingii has been carried out, mainly focused on the feeding habits [5], the reproductive biology [1,6,7] and arti cial breeding [8].…”

Effect of water temperature on the behavior of Neptunea cumingii and the histology, immune enzyme activity, and transcriptome of its gills and kidneys

“…Their results suggested that the loci could be used as markers for population and kinship analyses in this species. Hao et al (2020) studied the copulation, egg laying, embryonic development and changes in amino acids and fatty acids in N.cumingii during embryogenesis to understand the embryo development process and nutritional requirements in the early life phase. whose results showed that N.cumingii had direct development within the egg capsule and the development of embryos was classified into five stages.…”