Meso and microhabitat analysis and feeding habits of small nektonic characins (Teleostei: Characiformes) in Neotropical streams

Aquatic insects are considered a key component for stream food webs because of their contribution to the flow of energy from basal resources to the top predators. For this reason, the study of trophic guilds on aquatic insects is necessary to understand the transformation of energy and matter in stream ecosystems. The study of trophic guilds on aquatic insects has been widely documented in temperate streams. In contrast, little is known about feeding habits and trophic guilds in Neotropical streams. However, several lines of evidence indicate that aquatic insects in the Neotropical region are generally omnivores and that the Fine Particulate Organic Matter (FPOM) is the main food item. To test this hypothesis, we analyzed the diets and the trophic guilds of aquatic insects in an unexplored region of northern Colombia (Molino River, La Guajira). Aquatic insects were sampled using a Surber net, covering the different kind of substrates over a 100 m reach. Samples were sorted and identified to the lowest taxonomic level possible. We analyzed 250 guts of aquatic insects belonging to six orders, nine families, and 10 genera (Leptonema, Chimarra, Anacroneuria, Nectopsyche, Tabanus, Simulium, Pseudodisersus, Corydalus, Camelobaetidius, and Baetodes). We found that FPOM, algae, and animal tissue were the most important food items in the gut content of the aquatic insects at the Molino River. Our results suggest that aquatic insects in the Molino River are generally detritivores, highlighting the importance of the dead organic matter in Neotropical streams. We reported -for the first time- the trophic guilds of the genera Nectopsyche and Pseudodisersus, which were categorized as herbivorous. Our results suggest that aquatic insects in the Molino River exploit a variety of food resources and emphasize the importance of the study of feeding habits on aquatic insects in unexplored Neotropical streams.

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Food and feeding habits of juvenile flounder Platichthys flesus (L.), abd turbot Scophthalmus maximus L. in the åland archipelago, northern Baltic Sea

Netherlands Journal of Sea Research ◽

10.1016/s0077-7579(96)90058-7 ◽

1996 ◽

Vol 36 (3-4) ◽

pp. 311-320 ◽

Cited By ~ 1

Author(s):

K Aarnio

Keyword(s):

Baltic Sea ◽

Feeding Habits ◽

Scophthalmus Maximus ◽

Platichthys Flesus ◽

Food And Feeding ◽

Turbot Scophthalmus Maximus

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Utilizing next-generation sequencing to identify prey DNA in western North Atlantic grey seal Halichoerus grypus diet

Marine Ecology Progress Series ◽

10.3354/meps13520 ◽

2020 ◽

Vol 655 ◽

pp. 227-240

Author(s):

KR Flanders ◽

ZH Olson ◽

KA Ono

Keyword(s):

Next Generation Sequencing ◽

Feeding Habits ◽

Atlantic Menhaden ◽

Halichoerus Grypus ◽

Frequency Of Occurrence ◽

Grey Seal ◽

Next Generation ◽

Significant Difference ◽

Generation Sequencing ◽

Seal Diet

Increasing grey seal Halichoerus grypus abundance in coastal New England is leading to social, political, economic, and ecological controversies. Central to these issues is the foraging ecology and diet composition of the seals. We studied grey seal feeding habits through next-generation sequencing of prey DNA using 16S amplicons from seal scat (n = 74) collected from a breeding colony on Monomoy Island in Massachusetts, USA, and report frequency of occurrence and relative read abundance. We also assigned seal sex to scat samples using a revised PCR assay. In contrast to current understanding of grey seal diet from hard parts and fatty acid analysis, we found no significant difference between male and female diet measured by alpha and beta diversity. Overall, we detected 24 prey groups, 18 of which resolved to species. Sand lance Ammodytes spp. were the most frequently consumed prey group, with a frequency of occurrence (FO) of 97.3%, consistent with previous studies, but Atlantic menhaden Brevoortia tyrannus, the second most frequently consumed species (FO = 60.8%), has not previously been documented in US grey seal diet. Our results suggest that a metabarcoding approach to seal food habits can yield important new ecological insights, but that traditional hard parts analysis does not underestimate consumption of Atlantic cod Gadus morhua (FO = 6.7%, Gadidae spp.) and salmon Salmo salar (FO = 0%), 2 particularly valuable species of concern.

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