your fish are spawning…now what? adventures in marine live feeds
Transcription
your fish are spawning…now what? adventures in marine live feeds
YOUR FISH ARE SPAWNING…NOW WHAT? ADVENTURES IN MARINE LIVE FEEDS Eric J. Cassiano University of Florida Tropical Aquaculture Laboratory 1408 24th Street S.E. Ruskin, FL 33570 • Demersal Spawners ~4-7 days to hatch → Feed that day • Pelagic Spawners ~1 day to hatch → ~2-3 days to feed Clownfish eggs/larvae http://www.bluevisions.eu http://www.flickr.com/photos/luko/9283703717/ Diversity of Newly Hatched Larvae Ocellaris Clownfish Striped Blenny Sergeant major Bundoon Blenny Comet Courtesy Matthew L. Wittenrich Courtesy Matthew L. Wittenrich Live Feeds • Used during the early feeding phase of most fish larvae (marine and freshwater) – Higher survival, growth, performance – Prepared diet not developed for most species • Used during broodstock acclimation -Micscape Magazine Live Feeds in Marine Fish Aquaculture • ‘Traditional’ = wide spread use – Microalgae – Rotifers – Brine shrimp • ‘Alternative’ = limited use – Copepods – Ciliates – Bivalve larvae – Barnacle larvae – Others… Microalgae • Numerous species used – Tahitian strain Isochrysis galbana (T-ISO) – Nannochloropsis oculata – Chaetoceros gracilis – Pavlova sp. • Direct / Indirect nutrition – Active consumption (dinos) – Passive consumption – Food for prey • Shading Microalgae • Vessels • Starters • Carboys • Mass • Cultures • Batch • Continuous Credit: Bay Shellfish Co., manufacturer of the SeaCAPS systems in the Americas Rotifers • 2000 species described • Brachionus sp. (~100 µm BW) – B. plicatilis (L-strain) – B. ibericus (S-strain) – B. rotundiformis (SS-strain) • Accepted by marine fish larvae • Ease of culture – Dense = ~1000/mL – Algae paste – Tolerance to water quality issues – Enrichments Rotifers • • • • Colurella adriatica Estuarine rotifer (Tampa Bay) Picture ID (UF) Culture parameters – – – − 15 g/L optimal 300 rotifers/mL Algae paste / bacteria (?) ~45 µm BW Rotifers Aquaculture 315:355-360 (2011) • Proales similis – 40 µm BW – Mass cultured Brine Shrimp • 7-8 Artemia sp. (?) • Most widely used live feed • Produce cysts, timed hatching http://agsolution.com/28/artemia-cysts Brine Shrimp • Accepted by marine fish • Large size (450 µm - 12 mm) • Secondary feed • Adults used to wean broodstock • Microalgae / Enrichments http://jcoll.org/genoma/vida_microsubmarina/crustaceos/artemia.html Copepods • ~27,000 species described • Dietary component of many wild marine fish larvae • Small size (40 µm - 1 mm) • Appetite stimulatory effect • Maintenance can be variable Copepods • Cyclopoida – Accept a variety of diets ?? – Nauplii harvest suited for automation – Variable taxonomic group • Harpacticoida – Highest densities – Epibenthic, wide range H2O quality – Accept a variety of diets (prepared diet) • Calanoida – Well developed production systems – Egg collection and storage – Most need live microalgae Generalized Life Cycle (P. pelagicus) Nauplii (~90µm) Copepodite (~400µm) Adult with egg sacs (~1mm) Ciliates • Strombidium sp. – Crosshatch Triggerfish • Fabrea salina – Red Snapper • Euplotes sp. – Golden neon goby – Pacific blue tang • Balanion sp. – Atlantic cod • Stalked ciliates • Variable maintenance • Used as initial feed • Quickly grow and reduce water quality Other Live Feeds • Mollusc larvae (clams, oysters) – Commercially available – Known diet of some fish • Barnacle larvae • Annelid larvae • Nudibranch larvae http://www.flickr.com/photos/viucsr/7417983618/ – Bulla striata • Wild zooplankton – Sieve and bloom – Sterilize ? http://www.microscopy-uk.org.uk What Now ?? Typical First Feeding Regime -Main et al., 2007; SRAC 7206 • Florida pompano, developed at Mote Marine Laboratory • Nannochloropsis sp. (paste or live) Environment • Tank size (Larger is better…water quality) – May vary with species – Live feed density • Air flow – Heavy / light (oxygen levels) • Water – Movement – Shading (live microalgae / paste / clay) • Lighting – Photoperiod / wavelength Feeding • Feed appropriately – Low fish larval density ???? • Rotifers – Multiple feedings of enriched rotifers (4-5x daily) – System designed to flush excess • Copepods – Single daily feedings – System designed to retain excess • Artemia (2nd feeding) – Start slow while co-feeding – Wean onto pellets as soon as you can Monitoring • Water quality…water quality…water quality • Understand your water source • Microscope – Larvae – Live feeds – Tank • Assistance – Extension agents – “Specialists” (Rising Tide Conservation) – Hobbyists forums Live Feed Resources • Plankton Culture Manual Hoff, F.H. and Snell, T.W. (1987) • Manual on the Production and Use of Live Food for Aquaculture Lavens, P., Sorgeloos, P. (1999) • Live Feeds in Marine Aquaculture Stottrup, J.G. and McEvoy, L.A. (2003) • Copepods in Aquaculture Lee, C-S., O’Bryen, P.J., Marcus, N.H. (2005) Contact Information: Eric J. Cassiano University of Florida Tropical Aquaculture Laboratory 1408 24th Street S.E. Ruskin, FL 33570 Phone: (813) 671-5230 ext. 114 Email: ericcass@ufl.edu Web: http://tal.ifas.ufl.edu/index.htm