OCEAN FISH class OSTEICHTHYES 2 subclasses 45 ORDERS

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

OCEAN FISH DYNAMICS THE PELAGIC REPRODUCTIVE STRATEGY Class OSTEICHTHYES (PISCES) Subclass ACTINOPTERYGII Superorder TELEOSTEA Order CLUPEIFORMES 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 Herring Anchovy Sardine

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

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

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

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

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

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

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 Haddock Distinct demersal populations (and distinct spawning areas) in the NW Atlantic Three dorsal fins Larvae pelagic for long times (months)

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

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

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

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