1. OCEAN FISH
Sunfish 2,300 Kg
class OSTEICHTHYES
2 subclasses
45 ORDERS
450 FAMILIES
28,000 SPECIES
subclass ACTINOPTERYGII
40 ORDERS
435 FAMILIES
25,880 SPECIES
Oarfish 11 m
Leedsichthys problematicus †
(middle Jurassic)

2. OCEAN FISH DYNAMICS
THE PELAGIC REPRODUCTIVE STRATEGY
Class OSTEICHTHYES (PISCES)
Subclass ACTINOPTERYGII
Superorder TELEOSTEA
Order CLUPEIFORMES
Herring
Anchovy
Sardine
Internal skeleton with cellular bone
Cycloid scales
Caudal fin homocercus
Pelvic fins in abdominal position
Physostomes the gas bladder is connected with the esophagous with a duct

3. OCEAN FISH DYNAMICS
THE PELAGIC REPRODUCTIVE STRATEGY
Class OSTEICHTHYES (PISCES)
Subclass ACTINOPTERYGI
Superorder TELEOSTEA
Order CLUPEIFORMES
Engraulis enchrasicolus
Differently from other fishes
The average size of specimens seems to be not affected by population density
Clupeiformes are filter feeders

4. OCEAN FISH DYNAMICS
THE PELAGIC REPRODUCTIVE STRATEGY
Abundance peaks are synchronous between populations of different geographic areas
Engraulis encrasicolus
Sardina pilchardus
Clupea arengus

5. OCEAN FISH DYNAMICS
THE PELAGIC REPRODUCTIVE STRATEGY
Engraulis encrasicolus
Sardina pilchardus
Clupea arengus

6. OCEAN FISH DYNAMICS
THE PELAGIC REPRODUCTIVE STRATEGY
SARDINES AND ANCHOVIES
SMALL PELAGIC FISH SHOWING IMPRESSIVE POPULATION SIZES
LARGE AMOUNTS OF LARVAE AND JUVENILES OFTEN STAY IN VERY LOW PRODUCTIVE AREAS

7. OCEAN FISH DYNAMICS
THE PELAGIC REPRODUCTIVE STRATEGY
Class OSTEICHTHYES (PISCES)
Subclass ACTINOPTERYGII
Superorder TELEOSTEA
Order PERCIFORMES
Family TUNNIDAE
Cycloid scales
Caudal fin homocercus moonshaped
Pelvic fins in pectoral position
Spines on the caudal pedunculus
Albacore:
Large migrations in the Pacific Ocean
Larvae and juveniles voracious, in the surface layer
The spawning area is the NE Central Pacific Gyre

8. OCEAN FISH DYNAMICS
THE PELAGIC REPRODUCTIVE STRATEGY
Class OSTEICHTHYES (PISCES)
Subclass ACTINOPTERYGII
Superorder TELEOSTEA
Order PERCIFORMES
Family TUNNIDAE
Cycloid scales
Caudal fin homocercus moonshaped
Pelvic fins in pectoral position
Spines on the caudal pedunculus
Distributed allover the Atlantic ocean
Its spawning area in the W atlantic is restricted to the Mexico Gulf
Where it is attracted by the water front area, even if at many m below the thermocline

9. OCEAN FISH DYNAMICS
THE PELAGIC REPRODUCTIVE STRATEGY
Class OSTEICHTHYES (PISCES)
Subclass ACTINOPTERYGII
Superorder TELEOSTEA
Order GADIFORMES
Family GADIDAE
Caudal fin homocercus subtrinagular
Pelvic fins in pectoral position
Three dorsal fins
Haddock
Distinct demersal populations (and distinct spawning areas) in the NW Atlantic
Larvae pelagic for long times (months)

10. OCEAN FISH DYNAMICS
THE PELAGIC REPRODUCTIVE STRATEGY
Class CEPHALOPODA
Subclass COLEOIDEA
Superorder DECAPODIFORMES
Order THEUTIDEA
Family OMMASTREPHIDAE
8 + 2 arms
Short triangular fins
Illex illecebrosus
Very large, although variable, populations in the Atlantic Ocean
Large egg masses (in captivity) never found in nature;
Larvae of size growing with the distance from Florida

11. OCEAN FISH DYNAMICS
THE PELAGIC REPRODUCTIVE STRATEGY
Subphylum CRUSTACEA
Class MALACOSTRACA
Subclass EUMALACOSTRACA
Order DECAPODA
Infraorder BRACHYURA
Family PORTUNIDAE
Posterior legs used for swimming
Blue crab
Callinected sapidus
Adults go to the bay mouth
for the larvae release,
larvae stay in the upper layer,
Juveniles come back into the bay

12. . . . . . . . OCEAN FISH DYNAMICS THE PELAGIC REPRODUCTIVE STRATEGY
WATER
SEDIMENT
AIR .
WATER
SEDIMENT
AIR . . . . .

13. . OCEAN FISH DYNAMICS THE PELAGIC REPRODUCTIVE STRATEGY WATER, denser
SEDIMENT
AIR
WATER, lighter
THERMOCLINE/HALOCLINE
WATERFRONTS
RIVER PLUMES
Fish Aggregating Areas