what are the major candidate species for aquaculture?....(Important Candidate Species in Aquaculture)

 

Important Candidate Species in Aquaculture

Live Foods

Live foods are essential in aquaculture and include both phytoplanktonic and zooplanktonic organisms.

Phytoplankton

• Definition: Photosynthetic organisms that contain chlorophyll.
• Examples:
• Microcystis
• Volvox
• Eudorina
• Oscillatoria
  

Zooplankton

• Definition: Plankters of animal origin.
• Types:
1. Protozoans:
• Examples: Arcella sp., Difflugia sp., Actinophrys sp., Vorticella sp.
2. Rotifers:
• Examples: Brachionus spp., Keratella sp., Asplanchna brightwelli, Polyarthra vulgaris, Filinia opoliensis.
3. Crustaceans:
• Examples: Artemia spp., Moina spp., Daphnia spp., Ceriodaphnia sp.
4. Ostracoda:
• Examples: Cypris, Stenocypris, Eucypris.
5. Copepods:
• Examples: Mesocyclops leuckarti, M. hyalinus, Microcyclops varicans, Heliodiaptomus viduus.

Important Live Feeds

• Microbes
• Microalgae
• Infusoria
• Rotifers
• Artemia
• Copepods
• Cladocerans: Daphnia and Moina
• Tubifex
• Chironomid Larvae

Yeast

• Definition: Eukaryotic, single-celled microorganisms.
• Characteristics:
• Size: Typically 3–4 µm, some up to 40 µm.
• Reproduction: Asexually by mitosis or budding.
• Uses:
• Primary food source for larvae.
• Ingredient in artificial larval diets.
• Probiotic for zooplankton and post-larval penaeid shrimps.

Microalgae

• Definition: Chlorophyll-bearing unicellular or multicellular plants.
• Types:
• Chlorophyta (green algae)
• Phaeophyta (brown algae)
• Rhodophyta (red algae)

Importance in Aquaculture

• Serve as initial food producers in aquatic ecosystems.
• Nutritional attributes and small size (5 to 25 microns) make them ideal for early-stage aquatic animals.
• Used for rearing:
• Marine bivalve molluscs (clams, oysters, scallops)
• Gastropods (abalone, conch)
• Fish larvae (cod, halibut, tilapia)
• Shrimps (Penaeus sp.)

Nutritional Value

• Typically contains:
• 30 to 40% protein
• 10 to 20% lipid
• 5 to 15% carbohydrate
• Essential fatty acids:
•  DHA  (docosahexaenoic acid)
• EPA (eicosapentaenoic acid)
• AA(arachidonic acid)

Infusoria

• Definition: Microscopic single-celled organisms belonging to the class Ciliata of phylum Protozoa.
• Examples:
• Freshwater: Paramoecium, Stylonychia
• Marine: Fabrea, Euplotes
• Role: Ideal starter diet for early stages of fish larvae.

Rotifers

• Definition: Known as wheel animalcules.
• Importance: Serve as a crucial food source in aquaculture, particularly for fish larvae.

These live foods and microorganisms play a vital role in the growth and health of aquatic species in aquaculture.

Aquatic Organisms as Live Food

Rotifers

• Common Species: B. plicatilis and B. rotundiformis
• Characteristics:
• Euryhaline (tolerates various salinities)
• Small (50 to 200 microns)
• Slow swimming
• High nutritional value
• Nutritional Composition:
• 52% to 59% protein
• 13% fat
• 3.1% n-3 Highly Unsaturated Fatty Acids (HUFA)
• Importance:
• Ideal starter diet for fish and prawn larvae
• Demand increasing due to advancements in larval rearing technology
• Feeding Sources:
• Algae
• Baker’s yeast
• Artificial diets

Artemia (Brine Shrimp)

• General Information:
• Over 50 geographical strains identified
• Major source of live food in aquaculture
• Harvesting:
• 90% of commercial harvest from Great Salt Lake, Utah
• 200,000 to 300,000 nauplii hatch from each gram of cysts
• Advantages:
• Can produce live food on demand from dormant cysts
• High nutritive value and conversion efficiency
• All life stages (cysts, nauplii, juveniles) used as feed
• Commercial Use:
• 67 million-a-year industry
• Used in aquaculture, livestock feed, and even human consumption

Copepods

• Characteristics:
• Common zooplankton in freshwater and brackish water
• Size ranges from 0.5 to 5.0 mm
• Life Cycle:
• Six naupliar and six copepodite stages
• Lifespan: 40 to 50 days
• Feeding:
• Herbivorous, primarily filter feeders
• Can consume larger particles and detritus
• Reproduction:
• Female produces 250 to 750 fertilized eggs

Cladocerans

• Commonly Known As: Water fleas
• Important Species: Daphnia and Moina
• Classification:
• Order: Cladocera
• Sub-class: Branchiopoda
• Class: Crustacea
• Phylum: Arthropoda

Summary

• Rotifers, Artemia, copepods, and cladocerans are essential live food sources in aquaculture.
• Each has unique characteristics, nutritional values, and advantages for larval rearing of fish and crustaceans.