Week: 1

“Fish Physiology” Adopted from:

Dr. Eric B. May, Fish PhysiologySome General Processes

Feeding and DigestionGrowth and Metabolism

Dr. Ir. Happy NursyamFisheries and Marine Science Faculty

Brawijaya Universiya, Indonesia2009

Introduction

Active Transport Mechanisms

• A – Cosymport or symport movement of ions or molecules via ionic gate or macromolecule

• B – Antiport movement of ions or molecules via ionic gate or macromolecule

A

B

Trans-Membrane Transport of Macromolecules

• 1 Attachement of molecule to receptor or surface

• 2 Involution of surface• 3 Engulfment of molecule• 4 Pinching off and import of

macromolecule into the cell

Feeding and Digestion

My BestSubject

Feeding

Energy Budgets

Intake ( I = Income)• Macronutrients

– Carbohydrates– Fats/Oils– Proteins

• Micronutrients– Vitamins– Essential

• Fatty Acids• Amino Acids• Sugars

Energy Use (E = Expenditure)• Respiration• Osmoregulation• Movement• Feeding• Digestion

• Reproduction

IFI = E Growth = 0I < E Growth = I > E Growth = +

Diversity

• Again a Question of Adaptation

• Often – Consumer and Consumed Co-Evolve– Menhaden and Algae– Striped Bass and Menhaden

• Driver of Speciation – Exploitation of New Energy Resources

Capture and Ingestion

• Jaw and Mouth Action– Biting

• Blue fish – Bite, Shear• Eel – Bite, Rotate, Tear

– Swallowing• Striped Bass – Engulf, Digest, Expell

– Ram Feeding• Menhaden• Whale Shark

– Suction Feeding• Stone Rollers• Chubs

} Modification – Nipping, Parrot Fish

Body Shape

• Rover (Predators Usually)– Sharks– Bluefish– Tunas

• Lie in Wait (Ambush Predators)

– Gar– Pikes– Barracudas

– Monkfish– Anglerfish

} Streamlined – Torpedo Shape – Body Caudal Fin (BCF)

}Rear Oriented Fins – Instant Propulsion - BCF

} Pelvics and Pectorals Push Off, Tail for Propulsion

Body Shape (Continued)

• Surface Oriented Fish– Killifish– Flying Fish

• Surface Filter Feeders– Menhaden

• Bottom Fish– Flat Fish

• Deep Bodied Fish– Butterfly Fish– Angel Fish

• Eel Like Fish– Moray Eel– American Eel

Grouping by Diet

• Herbivores– Phytoplankton– Macrophytes

• Carnivores– Zooplankton

• Selective (High Cost but Food Specific)• Non-Selective (Low Cost but Non Specific)

– Benthic (Live in Water Column, but Feed Off Bottom)– Fish Feeders (Ichthyvores or Piscivores)

• Detritivores

Grouping by Diet (Continued)

• Herbivores

• Detritivores

• Carnivores}

Usually a function of co-adaptation of mouth and digestive tract, ie

1. Menhaden – Gizzard, elongated large intestine

2. Striped Bass – Muscular stomach, short intestines

3. Butterfly Fish – Coiled small and large intestines