Biology and impact of the New Zealand pea crab (Nepinnotheres novaezelandiae) in aquacultured greenlipped mussels (Perna canaliculus)
type: CreativeWork
description: Pea crabs are globally ubiquitous parasites of marine bivalves that cause serious economic impact among several major aquaculture species. However, little is known about the biology of pea crabs in aquaculture as well as their impact on the hosts and aquaculture production. There are many information gaps including host-parasite interactions and pea crab mating behaviour that could potentially prove useful for controlling their infection in aquaculture. Research presented in this thesis investigated the biology, abundance, distribution, impact, and mate location behaviour of Nepinnotheres novaezelandiae within aquaculture of its preferred host the New Zealand green-lipped mussel (Perna canaliculus). Systematic sampling of a typical green-lipped mussel farm revealed an overall farm-wide infection rate of 5.3 % of mussels. Crab abundance increased gradually with decreasing water depth beneath the farm and greater distance from the shoreline. Infection with a pea crab caused a 30 % reduction in total wet weight of the host mussel with shell dimensions also significantly reduced compared to mussels from the same farm without a pea crab. Extrapolating size losses to current total mussel aquaculture of green-lipped mussels in New Zealand represents an estimated loss of US$2.16 million annually. Sampling revealed a strong sex bias toward females (82.4 %) in the population of pea crabs surveyed on the mussel farm. Most crabs (87 %) recovered were sexually mature and of these 86.4 % were mature females. The sex ratio of immature crabs was relatively even indicating high post maturation mortality among male crabs. The pea crab population with the mussel farm was estimated at 126,390 with 93,000 gravid females carrying over 241 million eggs. These results indicate the rapid colonization and maturation of pea crabs in farmed mussels that are able to establish a significant breeding population with the potential for infecting nearby mussel farms as well as wild populations of bi…
abstract: Pea crabs are globally ubiquitous parasites of marine bivalves that cause serious economic impact among several major aquaculture species. However, little is known about the biology of pea crabs in aquaculture as well as their impact on the hosts and aquaculture production. There are many information gaps including host-parasite interactions and pea crab mating behaviour that could potentially prove useful for controlling their infection in aquaculture. Research presented in this thesis investigated the biology, abundance, distribution, impact, and mate location behaviour of Nepinnotheres novaezelandiae within aquaculture of its preferred host the New Zealand green-lipped mussel (Perna canaliculus). Systematic sampling of a typical green-lipped mussel farm revealed an overall farm-wide infection rate of 5.3 % of mussels. Crab abundance increased gradually with decreasing water depth beneath the farm and greater distance from the shoreline. Infection with a pea crab caused a 30 % reduction in total wet weight of the host mussel with shell dimensions also significantly reduced compared to mussels from the same farm without a pea crab. Extrapolating size losses to current total mussel aquaculture of green-lipped mussels in New Zealand represents an estimated loss of US$2.16 million annually. Sampling revealed a strong sex bias toward females (82.4 %) in the population of pea crabs surveyed on the mussel farm. Most crabs (87 %) recovered were sexually mature and of these 86.4 % were mature females. The sex ratio of immature crabs was relatively even indicating high post maturation mortality among male crabs. The pea crab population with the mussel farm was estimated at 126,390 with 93,000 gravid females carrying over 241 million eggs. These results indicate the rapid colonization and maturation of pea crabs in farmed mussels that are able to establish a significant breeding population with the potential for infecting nearby mussel farms as well as wild populations of bi…
author: Trottier, Oliver
license: https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm
date published: 2014
date modified: 2026-07-24T01:04:52Z
provider: University of Auckland
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: ResearchSpace@Auckland

PropertyValue
property ID: Handle
value: https://hdl.handle.net/2292/26890