Predator-Prey Interactions between Nonnative Juvenile Largemouth Bass (Micropterus salmoides) and Local Candidate Prey Species in the Pearl River Delta: Predation Capacity, Preference and Growth Performance.

Du Luo,Minghao Ye,Dingtian Yang

doi:10.3390/life12020295

Abstract

An ontogenetic dietary shift is crucial for the survival and growth of piscivorous largemouth bass (LB). However, there is much to learn about the predator-prey interaction during the switching process. We carried out a series of indoor experiments to examine the predation capacity, predation preference, and growth performance of exotic juvenile LB feeding on candidate prey species in the Pearl River Delta. The widely distributed oriental river prawn (Macrobranchium nipponense), barcheek goby (Ctenogobius giurinus), western mosquitofish (Gambusia affinis), silver carp (Hypophthalmichthys molitrix), and mud carp (Cirrhinus molitorella), with relatively similar total lengths, were selected as potential prey based on their availability and habitat use. Our results show that predation capacity and preference varied quantitatively and qualitatively among prey species. The number of oriental river prawns killed was significantly less than that of fish species, comparing the 1st hour with the 24th hour (p < 0.01). The feeding rhythm of LB varied significantly from crayfish to fish. Numerically, Jacobs’ selection index reinforced LB’s special preference for predating G. affinis. Although there were obvious variations in predation capacity and feed selection, no statistically significant growth differences were detected among LB groups feeding on live M. nipponense, G. affinis, H. molitrix, and C. molitorella (p < 0.05). These findings suggest that the successful ontogenetic dietary shift of juvenile LB may depend on the availability and vulnerability of local fish species. Further study on the reproductive phenology of potential fish prey may help to predict LB’s establishment.

Highlights

Introduction published maps and institutional affilForaging ecology is fundamental to understanding the detailed processes of individual development and community construction [1]
The juvenile bass predated as many as 22.5 ± 3.5 G. affinis in 24 h (PCN), significantly more than the other four prey groups (p < 0.05)
The predator could only consume 2.5 ± 1.0 g of M. nipponense in 24 h (PCW), which was significantly less than the other prey species, except from H. molitrix

Summary

Introduction

Introduction published maps and institutional affilForaging ecology is fundamental to understanding the detailed processes of individual development and community construction [1]. The ability to capture and ingest food is the key to the acquirement of nourishment from the environment that regulates the survival and growth of young individual fish. There is often an increase in feeding diversity and the forming of species-specific traits after the larval period in the diet ontogeny for piscivores freshwater fish. Fish species that predate fish earlier gain body scale advantages [2]. Morphology, behavior, and prey abundance are all crucial factors affecting the predatory selection of juvenile piscivorous fishes. Prey is not a passive victim, but capable of affecting predation with diverse functional traits [4]. Predator-prey interactions are critical drivers favoring the establishment of nonnative aquatic animals [5]

Methods

Results

Conclusion