Laboratory observations on predator–prey interactions between the bearded fireworm (Hermodice carunculata) and Mediterranean benthic invertebrates

We examined the hypothesis that fish species with similar ecomorphological patterns, but from different taxonomic groups, would use similar feeding modes. We contrasted the feeding behavior of Micropterus salmoides (Lacepede) (Centrarchidae) and Cichla ocellaris (Block and Schneider) (Cichlidae), both large-mouthed piscivores with a locomotor morphology designed for fast acceleration, with Lepomis spp. (Centrarchidae) and Cichlosoma severum (Heckel) (Cichlidae), both small-mouthed predators on benthic invertebrates with a locomotor morphology designed for maneuverability. Pressure profiles in the buccal and opercular cavities were more similar for species that shared ecomorphological patterns than for species that shared phylogenetic histories. For small- mouthed predators, minimum buccal pressures were significantly greater and occurred earlier than the corresponding opercular pressures. For both large-mouthed predators, minimum buccal and opercular pressures were similar in magnitude and in timing. We developed the ram-suction index (RSI) to identify the relative contributions of ram feeding (i.e. predator movement) and of suction feeding (i.e. prey movement) to shortening the predator-prey distance during the strike. The RSI values for small- mouthed predators fell closer to the suction end of the ram-suction continuum than did strikes by the large-mouthed predators. The RSI provides a bench mark for evaluating the hydrodynamic consequences of intraspecific, interspecific and interprey variation in strike mechanics.

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Field evidence for microplastic interactions in marine benthic invertebrates

Scientific Reports ◽

10.1038/s41598-021-00292-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Stefania Vecchi ◽

Jessica Bianchi ◽

Massimiliano Scalici ◽

Fabrizio Fabroni ◽

Paolo Tomassetti

Keyword(s):

Organic Matter ◽

Benthic Invertebrates ◽

Feeding Strategies ◽

Filter Feeder ◽

Hermodice Carunculata ◽

Field Evidence ◽

Definition Of ◽

Almost All ◽

Marine Benthic Invertebrates ◽

The Impact

AbstractMicroplastics represent an important issue of concern for marine ecosystems worldwide, and closed seas, such as the Mediterranean, are among the most affected by this increasing threat. These pollutants accumulate in large quantities in benthic environments causing detrimental effects on diverse biocenoses. The main focus of this study is on the ‘polychaetes-microplastics’ interactions, particularly on two species of benthic polychaetes with different ecology and feeding strategies: the sessile and filter feeder Sabella spallanzanii (Gmelin, 1791) and the vagile carnivorous Hermodice carunculata (Pallas, 1766). Since not standardized protocols are proposed in literature to date, we compared efficiencies of diverse common procedures suitable for digesting organic matter of polychaetes. After the definition of an efficient digestion protocol for microplastics extraction for both polychaetes, our results showed high microplastics ingestion in both species. Microplastics were found in 42% of individuals of S. spallanzanii, with a mean of 1 (± 1.62) microplastics per individual, in almost all individuals of H. carunculata (93%), with a mean of 3.35 (± 2.60). These significant differences emerged between S. spallanzanii and H. carunculata, is probably due to the diverse feeding strategies. The susceptibility to this pollutant makes these species good bioindicators of the impact of microplastics on biota.

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