Feeding patterns in seagrass beds of three-spined stickleback Gasterosteus aculeatus juveniles at different growth stages

Abstract

Today, three-spined stickleback Gasterosteus aculeatus are the most abundant fish in the White Sea and are close to their historical maximum. Based on observations from 2011–2013, this study reports quantitative and qualitative characteristics of juvenile stickleback diet during periods of active feeding in coastal Zostera seagrass beds. The following planktonic taxa dominated stomach contents: copepods Temora longicornis and Microsetella norvegica, ciliophora Helicostomella subulata. Benthic organisms such as Oligochaetae and Orthocladiinae also played an important role, whereas the literature suggests they were once rare in marine stickleback diets. Consumption patterns depended on fish size, with the most pronounced diet shift taking place as juveniles reached a length of 15 mm, in late August. In larger juveniles the highest correlation between the abundance of food organisms in stomachs and in the sea was observed for Orthocladiinae, suggesting that they are the preferred food. Overall, changes in diet followed changes in the abundance of available food organisms, but food selectivity analysis of planktonic organisms showed that M. norvegica were actively selected by juveniles.

Habitat preference of three-spined stickleback juveniles in experimental conditions and in wild eelgrass

“…It has been shown in three species of sticklebacks – G. aculeatus, Pungitius pungitius (L.) and Apeltes quadracus (Mitchill), that they prefer to stay in eelgrass growths even if such growths were located at a considerable distance from each other (Lazzari et al , 2003). Analysis of feeding of juvenile stickleback in the eelgrass beds in the area of our study shows that the fish prey on both planktonic and benthic forms and change their diet depending on size and availability (Demchuk et al ., 2015; Rybkina et al ., 2016 in press). Therefore we may conclude that eelgrass may provide more effective shelters and better feeding conditions than other habitats.…”

Imprecise naming: the anadromous and the sea spawning threespine stickleback should be discriminated by names

“…Thus, sampling of threespine sticklebacks in the ocean (Barber 2003;Kristjansson 2005;Marchinko 2009;Schade et al 2014) is not a guarantee of having sampled a strictly marine stickleback. Therefore, Bmarine^should only be used where the specimens were observed or sampled at a marine spawning site (Bell and Peeke 2012;Demchuk et al 2015), i.e. both terms should be selfdescribing.…”

Morphological Variation of Threespine Stickleback (Gasterosteus Aculeatus) on Different Stages of Spawning Period

“…Пространственное распределение колюшки в прибрежной зоне в летний нерестовый период в значительной степени связано с зарослями морской травы Zostera marina , предоставляющей благоприятные кормовые условия и укрытия для молоди [Demchuk et al, 2015;Rybkina et al, 2016] и взрослых рыб [абдель-Малек, 1963; демчук и др., 2018]. в то время как самцы относительно слабо питаются на нерестилищах из-за заботы о потомстве, самки колюшки не отличаются территориальным поведением и регулярно компенсируют нерестовые энергозатраты за счет питания [Van den assem, 1967].…”

“…Климат может влиять на численность популяций колюшки как напрямую, путем изменения физиологических параметров особей, так и опосредованно, расширяя экологические ниши обитания или изменяя численность и доступность пищевых организмов [Lefebure et al, 2011]. Поскольку колюшка сейчас является самым многочисленным видом рыб белого моря , активно потребляет разнообразные пищевые организмы [Demchuk et al, 2015;демчук и др., 2018], сама играет важную роль в питании массовых хищных рыб [Bakhvalova et al, 2016] и является важным звеном в паразитарных цепях [Rybkina et al, 2016], изучение популяционной биологии трехиглой колюшки в белом море может не только помочь оценить последствия изменений окружающей среды для этого вида, но лучше понять механизмы влияния климата на всю экосистему.…”