Fatty acid comparison of four sympatric loliginid squids in the northern South China Sea: Indication for their similar feeding strategy

Abstract

Feeding strategies of sympatric squid species help to understand their role in marine ecosystems. Four loliginid squids, Uroteuthis duvaucelii, Uroteuthis edulis, Uroteuthis chinensis, and Loliolus uyii are the major cephalopod species in the coastal waters of the northern South China Sea, where they occur together. We investigated their feeding strategies in terms of foraging behavior and habitat use by comparing fatty acid profiles and spatial distributions. There were no significant differences in the proportions of saturated or polyunsaturated fatty acids among species. Similar findings were obtained for most individual fatty acids that made up of an average of more than 84% of total fatty acid content for each species. Substantial overlap and high similarity in the fatty acid composition were observed. However, there were no significant effects of individual size or sampling station on the fatty acid compositions. The spatial overlap analysis demonstrated that there was clear spatial segregation and habitat use among the species. Cumulatively, our results suggest that the four squids are opportunistic carnivores, unselectively foraging on similar prey items, while spatial segregation is likely a major mechanism leading to their coexistence in the northern South China Sea.

High‐throughput sequencing and fatty acid profile analyses of the Black Amur bream (Megalobrama terminalis) reveal variation in dietary niche associated with geographic segregation

“…The differentiation of trophic niches can be a sign of interspecific feeding differences and habitat differentiation (Gao et al, 2018). Interspecific spatial isolation is an effective method of alleviating competition for food resources (Lin et al, 2020). fish diet significant affected the tropic niche width of M. terminalis.…”

The Role of Environmental Factors on the Fishery Catch of the Squid Uroteuthis chinensis in the Pearl River Estuary, China

“…Studies on habitat utilization and feeding behavior of four different species of squid (U. duvaucelii, U. edulis, U. chinensis and Loliolus uyii) in the northern SCS showed that although the feeding strategy was similar, their habitats did not overlap. This spatial segregation could reduce their competition for resources and buffer their trophic interactions, thus increasing the possibility of the species coexisting in the region [22].…”

“…The available studies on the U. chinensis in the SCS are all focused on biological characteristics [18][19][20], migration the catch of Ommastrephes bartramii in the northwestern Pacific to a great extent [16,17]. The available studies on the U. chinensis in the SCS are all focused on biological characteristics [18][19][20], migration characteristics [21], feeding behavior [22], and resource status [23]. Studies showed that U. chinensis did not migrate on a large scale, but moved in short distances according to local water temperature.…”

“…In addition, a large amount of fresh water is discharged from the PRE every year, mixing with seawater to form the Pearl River plume [28], which radiates to the coastal waters [29]. Because of these dynamic characteristics, the PRE boasts a high primary productivity [22,30], making it one of the major fishing grounds for U. chinensis in the world [31]. Therefore, the status of U. chinensis stock in the PRE is of great research value.…”

Fatty Acid Profile of Jumbo Squid (Dosidicus gigas) off the Peruvian Exclusive Economic Zone: Revealing the Variability of Feeding Strategies

“…Here, we used fatty acid analysis to investigate the variability of feeding strategies and trophic niche among these three groups off the Peruvian exclusive economic zone. As the fatty acids of a heterotrophic organism effectively reflect those in its diet [37], this study was designed to (1) determine the differences in fatty acid composition and trophic niche among three groups, (2) explore the variability of fatty acid composition between sexes, and (3) evaluate the feeding strategy of three groups of D. gigas. This study provides the basis for understanding the variability of feeding strategy and coexistence mechanism among groups and sexes.…”