Biochemical composition during the reproductive cycle of a novel gastropod resource from Atlantic Patagonia

The seasonal changes in biochemical composition of the edible bivalve Arca noae harvested from a Mediterranean coastal lagoon (Bizerte lagoon, Tunisia) were investigated from October 2013 to September 2014. Potential food sources and nutritional quality indices (NQI) were determined by analyzing the fatty acid profiles of their tissues during an annual reproductive cycle. Results showed that A. noae had moisture (73.8–82%) and protein (24.1–58.6% dry weight) as major components, followed by lipid (10.4–28.8% dry weight) and glycogen (4.05–14.6% dry weight). A. noae accumulated lipid and glycogen for gonadal development during both maturation periods (late autumn/late spring–summer) to be used during spawning periods (winter/late summer–early autumn). However, proteins were mainly used to support reproductive allocation and played an important role on the energetic maintenance. Lipid and glycogen were found to be significantly related to temperature, salinity and chlorophyll a (p < 0.05). An increase of condition index (CI) was observed during spring and early summer when both temperature and food supply increased. The total fatty acid (TFA) profile of Ark shells was dominated by polyunsaturated fatty acids (PUFA) (33.8–49.6%), followed by saturated (SFA) (29.1–43.1%) and monounsaturated fatty acids (MUFA) (20.77–28.3%). A. noae soft tissues were also rich in macro-minerals (Na, Ca and Mg). The analysis of fatty acid trophic markers revealed that the diet of A. noae during the year of study was based on mixture food mainly on phytoplankton followed by zooplankton and other sources (bacteria, seagrass and macroalgae). Furthermore, the nutritional quality indices have revealed that A. noae is an excellent source of nutrients and a healthy food for human consumption. These data are useful to the conservation of natural stocks of A. noae and the development of sustainable aquaculture production of this shellfish species in the Bizerte lagoon.

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Seasonal variations in biochemical composition during the reproductive cycle of the intertidal gastropod Thais lamellosa Gmelin (Gastropoda, Prosobranchia)

Canadian Journal of Zoology ◽

10.1139/z74-038 ◽

1974 ◽

Vol 52 (3) ◽

pp. 305-318 ◽

Cited By ~ 63

Author(s):

Philip Lambert ◽

Paul A. Dehnel

Keyword(s):

Digestive Gland ◽

Reproductive Cycle ◽

Seasonal Variations ◽

Biochemical Composition ◽

Feeding Activity ◽

Lipid Reserve ◽

Low Level ◽

Biochemical Constituents ◽

Histological Sections ◽

Intertidal Gastropod

Seasonal variations in biochemical constituents of Thais lamellosa Gmelin in relation to the reproductive cycle were studied. Digestive gland, foot muscle, and gonad were analyzed for protein, glycogen, lipid, and ash for 1 year. Data on feeding and gamete maturation were obtained from histological sections of digestive gland and gonad. Major periods of feeding activity occurred in April and August. The spawning peak was in March and gametogenesis began in July. Maximum glycogen levels coincided with major feeding periods but reserves in the digestive gland were mainly lipid. This lipid reserve was used during the winter. Glycogen was at a relatively low level in all tissues and appeared to be used by the developing gonad. The foot muscle stored neither lipid nor glycogen to any appreciable extern.During winter the digestive gland index decreased as reserves were used. The ovary index held constant from October to February then dropped sharply with spawning. Animals kept for the same period under artificial summer conditions showed no decrease in the digestive gland index, but a decrease in the ovary index. Few oogonia reached maturity and many were resorbed. Starved animals used more protein from the ovary than fed animals.

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