Reproductive strategy of the invasive green mussel may result in increased competition with native fauna in the southeastern United States

Katherine Mcfarland,Aswani Volety,Philippe Soudant,Fred Jean

doi:10.3391/ai.2016.11.4.06

Abstract

Understanding the population dynamics of invasive species, such as the green mussel Perna viridis (Linnaeus, 1758), can aid in explaining the success of newly introduced populations and help predict the potential for spread. During a two-year field study of established populations in the invaded region of southwest Florida, year round gametogenesis and continuous spawning capabilities were observed through histological analysis of mussels collected monthly. This was supported by overall stable energetic reserves as measured through proximal biochemical composition (protein, glycogen and lipid content). However, egg outputs in the summer (6.4 × 10 6 ± 2.6 × 10 6 eggs / female) were significantly higher than egg outputs of winter-spawned mussels (7.7 × 10 4 ± 1.4 × 10 4 eggs / female). Stability in biochemical composition, suggests temperature and food availability were sufficient year round, allowing for the maintenance of reserves and active gametogenesis. Protein ranged from 409.0–628.0 mg g −1 , glycogen from 44.3–158.5 mg g −1 and total lipids from 7.4–13.5 mg g −1. Year-round reproductive capabilities supported by sufficient energy reserves may help explain the rapid colonization and high densities of green mussels along the southeastern United States and suggests the potential for competition with native species, particularly the eastern oyster Crassostrea virginica (Gmelin, 1791).

Highlights

The green mussel Perna viridis (Linnaeus, 1758) is a recent marine invader to southwest Florida, USA
P. viridis are well studied as an aquaculture species and bio-indicator for marine pollutants in its native range, little is known of invasive populations and their potential ecological impact on native bivalve populations in the southeastern United States
There was seasonal variation in the environmental variables measured during the study period these values remained within the documented tolerance range of P. viridis (Vakily 1989)

Summary

Introduction

The green mussel Perna viridis (Linnaeus, 1758) is a recent marine invader to southwest Florida, USA. First detected in Trinidad and Tobago in the early 1990’s (Agard et al 1992), they have aggressively spread throughout coastal waters of the Caribbean and southeastern United States (Rylander et al 1996; Benson et al 2001; Ingrao et al 2001; Buddo et al 2003; Baker et al 2007). P. viridis are well studied as an aquaculture species and bio-indicator for marine pollutants in its native range, little is known of invasive populations and their potential ecological impact on native bivalve populations in the southeastern United States. Green mussels reach sexual maturity within the first few months of settlement (Rao et al 1975; Sreenivasan et al 1989), achieving average growth rates of 6–10 mm month−1 (McFarland et al 2016), and dominate hard substrates at densities as high as 1000–4000 individuals m−2 (Fajans and Baker 2005). Concerns abound regarding the future range expansion of the invasive P. viridis and potential competition with the native oyster C. virginica

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