fishes

Introduction
- Almost half of all species of animals with backbones (vertebrates) are fish
- Over 21,000 species from warm water of coral reefs to the cold waters of Antartica
- The diversity and abundance of fishes vary with latitude and longitude: from east to west, the greatest diversity is found in the south-eastern Asian region of Indo-Pacific (centre of evolution)
- Along a north to south axis, the greatest diversity is generally found in low tropical latitudes and decreases towards Polar Regions.
- Temperate water fisheries are based on a single species; whereas in tropical waters fisheries are made up of many different species

Clupeid fish
- Consist of sardines, herrings, sprats and anchovies.
- Pelagic fish typical of upwelling areas
- Eaten fresh, canned and pickled, most is ground into fishmeal.
- Example of single species-fisheries:
- Japanese pilchard (Sardinops melanostictus)
- Peruvian anchovy (Engraulis ringens)
- Atlantic herring (Clupea harengus)

Temperate water demersal fishes
- Catches about 15% of the world total from North Atlantic
- Mostly distributed in cool waters of the northern hemisphere
- Cod (Gadus morhua) and the haddock (Melanogrammus aeglefinus) occur across North Atlantic from Europe to North America
- Hakes (fam. Merlucciidae) have wider temperature distribution
Tropical inshore fishes
- Several species are adapted to take advantage of the inshore productivity
- Flathead mullets (Mugil spp) and ponyfish (Leiognathus spp) have mouth suited for feeding on diatoms, filamentous algae and detritus.
- Goatfish (Mullidae) have sensitive barbells which aid in locating food
- Others: garfish (Hemiramphus spp), rabbitfish Siganus spp.
- Provide an easily accessible source of protein for subsistence fishers.
Deep-water fishes
- Snappers are caught by hook and line and by traps in depths of about 200 m
- Main species caught: genera Etelis sp., Pristipomoides sp and Apharus sp.
- Particularly valuable in tropical areas.
Open-Sea Fishes
- The best known open sea fish are tuna  fast swimming, pelagic fish.
- Warm-blooded and keep their body temperature higher than surrounding environment.
- Catches of tunas amount over 5% of the world catch
- Distant water fishing vessels fish for tuna using longlines to catch albacore, big-eye tuna and adult yellowfin tuna.
- Pole and line and purse seine are used to catch skipjack tuna and juvenile yellowfin tuna.
- Large stocks are found in upwelling area
- In Japan blue fin tuna (kuro maguro) is sold at the same price as new BMW or Mercedez-benz; eaten raw as sashimi.