Seasonal Variations in Maternal Provisioning of Crepidula fornicata (Gastropoda): Fatty Acid Composition of Females, Embryos and Larvae

Abstract

Recruitment success of marine invertebrate populations not only depends on the number of recruits but also on their quality which affects their survival. In species characterized by a mixed development (encapsulated embryonic development and release of planktotrophic larvae), the offspring quality depends on both maternal provisioning and larval feeding. Here, we investigated potential changes of maternal provisioning over the whole reproductive period in a gastropod with a mixed development: Crepidula fornicata . In its introduction area, C . fornicata reproduces from February to October, which implies that both adults and larvae are exposed to different food availabilities. Maternal provisioning was assessed by measuring the fatty acid (FA) composition of females, encapsulated embryos and larvae, in February, May, July and September 2009. FA are essential resources for the development of embryos and larvae, and are key biomarkers of offspring quality. Our results showed differences in FA composition between muscles, visceral masses, and encapsulated embryos. In particular, FA composition of embryos was similar to that of the visceral mass. Seasonal variations in FA composition were observed: in the middle of the reproductive season (May and July), female tissues and embryos showed a higher proportion of polyunsaturated fatty acids and especially ω3, as compared to the beginning and end of the reproductive season (February and September). This showed that through maternal provisioning the quality of C . fornicata offspring was higher in the middle of the reproductive season. Whether this would result in an increase of recruitment success and juvenile performance would require further investigations.

Trophic niche of the invasive gregarious speciesCrepidula fornicata, in relation to ontogenic changes

“…As shown earlier with SI, all ontogenic stages of C. fornicata may have probably exploited SSOM before the spring bloom when food in the water column is less available. In this pool of OM, FA revealed that slipper limpets likely fed on benthic diatoms (as suggested by 16:1n-7 and 20:5n-3; Dunstan et al 1992;Napolitano et al 1997;Passarelli et al 2012), dinoflagellates (22:6n-3;Zhukova and Aizdacher 1995;Lavaud et al 2018) and bacteria (Branched FA and 18:1n-7;Perry et al 1979;Zhukova et al 1992;Haack et al 1994), which is in agreement with previous interpretations done in other comparable coastal bays Leroy et al, 2013). In sediment, bacteria are often associated with detritus and are therefore not considered as a high-quality food source (Dalsgaard et al, 2003).…”

“…They are energy reserves (neutral lipids) but also key structural component of cell membranes (polar lipids). In molluscs as for C. fornicata, such lipids storages are essential for larval development and during mature ontogenic stages for gonadal development (Deslous-Paoli and Héral, 1986;Leroy et al, 2013). Contrary to polar lipids, FA incorporated in the neutral fraction are directly mobilized and reflect more closely the FA composition of the diet (Fernández-Reiriz et al, 2015;Jezyk and Penicnak, 1966;Langdon and Waldock, 1981;Waldock and Nascimento, 1979).…”

Larval settlement and metamorphosis in a marine gastropod in response to multiple conspecific cues

“…Adult females were removed from their substrates to check for incubating egg capsules. Capsules with larvae that were ready to hatch (stage IV veligers sensu Leroy et al, 2013 ) were selected and hatched by physically agitating them in a bowl of filtered seawater at room temperature. Larvae from three females were combined for rearing in cultures of 800 ml of 1 µm-filtered seawater (FSW) at a concentration of one larva per four ml.…”

Состав жирных кислот в трохофорах мидий Mytilus galloprovincialis, выращенных в условиях загрязнённости полихлорбифенилами

“…Идентификация метиловых эфиров жирных кислот. Идентификация МЭЖК выполнена в ЦКП «Спектрометрия и хроматография» ФИЦ ИнБЮМ на газовом хроматографе Кристалл 5000.2 (ЗАО СКБ «Хроматэк», г. Йошкар-Ола, РФ) с квадрупольным масс-детектором и капиллярной колонкой DB-5ms (Agilent Technologies) длиной 30 м, с внутренним диаметром 0, 25 1,4 ± 0,6 0,6 ± 0,3 1,3 ± 0,4 1,0 ± 0,3 1,4 ± 0,5 Миристиновая (тетрадекановая) (C14:0) 6,2 ± 0,2 5,7 ± 0,6 7,7 ± 0,7 6,4 ± 0,4 6,5 ± 0,6 Пентадекановая (пентадециловая) (C15:0) 4,4 ± 0,8 5,3 ± 1,1 8,5 ± 0,5 5,8 ± 0,2 4,7 ± 0,7 Пальмитолеиновая (цис-9-гексадеценовая) (C16:1ω7) 11,0 ± 0,6 6,8 ± 0,6 7,0 ± 0,2 9,6 ± 0,4 10,8 ± 0,8 Пальмитиновая (гексадекановая) (C16:0) 29,3 ± 4,3 33,8 ± 0,4 30,1 ± 0,3 34,7 ± 0,6 31,7 ± 2,3 цис-10-гептадеценовая (C17:1ω7) 3,9 ± 1,5 1,2 ± 0,4 1,2 ± 0,2 1,4 ± 0,4 2,4 ± 1,5 14-метилгексадекановая (антеизо-C17:0) 2,4 ± 0,5 1,8 ± 0,3 2,3 ± 0,2 2,0 ± 0,1 2,6 ± 0,8 Арахидоновая (цис,цис,цис,цис-5,8,11,14эйкозатетраеновая) (C20:4ω6)…”

“…Концентрация незаменимой арахидоновой (C20:4ω6) кислоты в трохофорах не являлась постоянной величиной и варьировала в широком диапазоне от 1 до 21 %. Для сравнения: в гастроподах концентрация арахидоновой (C20:4ω6) кислоты достигала 5,73 % [25]. Как известно, живые организмы могут синтезировать арахидоновую (C20:4ω6) кислоту из незаменимой Омега-6-ненасыщенной линолевой кислоты [1].…”