Oyster larvae as a potential first feed for small-mouthed ornamental larval fish

Aj Basford,T Mishina,B Mos,Sa Dworjanyn

doi:10.3354/aei00338

Abstract

AEI Aquaculture Environment Interactions Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AEI 11:657-669 (2019) - DOI: https://doi.org/10.3354/aei00338 Oyster larvae as a potential first feed for small-mouthed ornamental larval fish Alexander J. Basford*, Benjamin Mos, Tomoki Mishina, Symon A. Dworjanyn National Marine Science Centre, Southern Cross University, Coffs Harbour, NSW 2450, Australia *Corresponding author: alex.basford@scu.edu.au ABSTRACT: Aquaculture of ornamental marine fish for the aquarium trade is a possible solution to the negative environmental impacts of wild collection. An impasse to the culture of many marine fish species is high larval mortality due to unsuitable live feeds. Common live feeds can be too large for ornamental species, which often have larvae with small mouths. We tested wild oyster larvae as an alternative live feed for first-feeding blue tang Paracanthurus hepatus. P. hepatus readily consumed oyster larvae but did not consume rotifers. Survival and growth of P. hepatus fed oyster larvae was similar to unfed controls, likely due to the oyster trochophores developing into indigestible veligers. Restricting the diet of P. hepatus to only oyster trochophores improved survival and eye development, but survival rates remained low. Oyster trochophores were conditioned in pH 4.8 seawater to compromise their aragonite shells, and P. hepatus fed these had higher survival at 5 d post-hatch (dph) compared to those fed untreated trochophores and were the only fish surviving to 10 dph. The high consumption rates of oyster larvae by P. hepatus highlight the potential for bivalve larvae to be used as live feeds for first-feeding larval fish. Further research into improving the nutritional value of oyster larvae for larval fish may improve their viability as first feeds. KEY WORDS: Acidification · Blue tang · Paracanthurus hepatus · Fatty acids · Live feeds · Larval rearing Full text in pdf format Supplementary material Corrections to supplement PreviousNextCite this article as: Basford AJ, Mos B, Mishina T, Dworjanyn SA (2019) Oyster larvae as a potential first feed for small-mouthed ornamental larval fish. Aquacult Environ Interact 11:657-669. https://doi.org/10.3354/aei00338 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AEI Vol. 11. Online publication date: December 05, 2019 Print ISSN: 1869-215X; Online ISSN: 1869-7534 Copyright © 2019 Inter-Research.

Highlights

The collection of ornamental marine fish for the aquarium trade can cause negative environmental impacts, including decreased biodiversity from overextraction and damage to habitats from destructive fishing practices (Lecchini et al 2006, Calado et al 2017)
The gut area of 5 dph P. hepatus fed oyster larvae combined with rotifers was not different from all other treatments (Fig. 3D)
We found that P. hepatus readily consumed oyster larvae, but almost never consumed rotifers

Summary

Introduction

The collection of ornamental marine fish for the aquarium trade can cause negative environmental impacts, including decreased biodiversity from overextraction and damage to habitats from destructive fishing practices (Lecchini et al 2006, Calado et al 2017). A key impasse to the commercialisation of many marine fish species is high mortality during the early larval stage due to a lack of suitable live feeds (Yúfera & Darias 2007, Hamre et al 2013). Poor first feeds are a common cause of mortality because larval fish have small energy reserves, high metabolic demands, and limited capacity to capture and digest food (Fisher et al 2007, Yúfera & Darias 2007, Rønnestad et al 2013). These limitations appear exacerbated in small fish larvae as they are more sus-. A lack of live feeds suited to fish larvae with small mouth

Methods

Results

Conclusion