Marine Biology 1060        Study guide for Chapter 7         Marine Fishes

Terms to know:

Phylum Chordata            protochordates            Dorsal nerve cord                pharyngeal gill slits
notochord                       pharynx                       cephalochordate                  sea squirt
lancelets                         Subphylum vertebrata    vertebral column                spinal cord
Backbone                      Class Agnatha                Hagfish                              Lamprey
Cartilaginous Fish           Class Chondrichthyes    Shark                                Skate
Ray                                placoid scales                Dermal denticles                caudal fin
dorsal fin                        pectoral fin                    pelvic fin                            claspers
Gill slits                          spiral valve                    squaline                              lateral line
Ampullae of Lorenzini     Bony Fish                   Class Osteichthyes             operculum
Gill arches                       ctenoid scales                swim bladder                      chromatophores
counter shading              Guanine                        irridiophores                       cryptic coloration
Disruptive coloration       gill rakers                     filter feeders                        gill lamellae
gill filaments                    counter current exchange                                        fish circulation
schooling behavior           Migration                    Anadromous                       Catadromous
leptocephalus larvae        metamorphosis             hermaphrodites                   sex reversal
oviparous                        ovoviviparous              viviparous                           sting ray
Manta Ray                     electric Ray

Concepts to know:

1. Know the importance of the protochordates as an ancestor to modern vertebrates. Know the examples we discussed and their characteristics. Lancelets and Tunicates (sea squirts). Know the characteristics shared by ALL chordates, that is: notochord, pharyngeal gills, dorsal nerve cord, segmented muscles. Know  the characteristics of organisms in the subphylum vertebrata.

2. Know the classes Agnatha, Chondrichthyes and Osteichthyes. Know the characteristics that place them in these groups.
    a. Agnatha: jawless fishes. No lower jaws, no paired fins, gills in separate chambers. Similar to the earliest vertebrates.

    b. Chondrichthyes: Cartilaginous fishes. Skeleton consists of cartilage. Lower jaws evolved from gill arches. Primitive sharks have 7 gill slits, advanced sharks have 5. The spiracle is a remnant gill opening (vestigial).  Jaws not attached to skull. paired fins. placoid scales. Teeth evolved from placoid scales. Teeth in multiple rows. Pelvic fins, pectoral fins, dorsal fins, caudal and anal fins. Each gill in a separate cavity with it's own gill slit. Spiral valve in the intestine. No swim bladder, use squaline oil in tissues for bouancy. Store urea in their tissues. two chambered heart and single loop circulatory system. Most are carnivorous, though some are filterfeeders. H highly developed sensory systems including electro-reception. Know sensory abilities of sharks which we discussed in class.

    c. Osteichthyes: Bony fishes. Skeleton of true bone. most have a swim bladder that can be filled with oxygen for bouancy regulation. scales are ctenoid. two chambered heart and single loop circulatory system. development of complex skulls with dermal bone was an important evolutionary advance in this group. Specialization of jaws and feeding allowed great diversification. Gills supported on bone arches and all gills are in a single cavity covered by an operculum.

3. Know gill structure and how counter current exchange functions in gills and in heat conservation for warm bodied fishes, etc. Know how water is moved over the gills and characteristics of water related to extracting oxygen from it.

4. Know uses of color that has evolved in fish and terminology related to it.

5. know the characteristics of fish body form that are related to swimming and life history. For example, shape and structures that occur as adaptations to fast swimming in pelagic fish such as tuna, great white sharks, etc.

6. Know the parts and structure of fish circulatory systems.

7. Know the reproduction types found in sharks and fishes. Live birth, egg laying, ovovivipary, etc. Know the examples of sex reversal discussed in class.

8. Know the examples of fish migrations discussed in class. Anadromous and catadromous. Know where the examples breed and how Salmon return to their home stream.

9. Notes from class on specific fish discussed are fair game. Some important examples are :

    White Shark - pelagic predator, warm body temperature, breaching behavior off South Africa, man killer
    Bull Shark - Number one man killer. Found in many inshore waters.
    Tiger shark
    Mako Shark
    Whale Shark - world's largest fish - harmless filter feeder.
    Electric ray - can deliver 200 + volts
    Manta Ray- large filter feeder
    Sting rays - two spines on the tail with associated venom glands
    Tuna, mackerel, etc. - fastest swimmers. Up to 45 mph. adaptations include: Finlets acting as spoilers,
                                    slots for tucking away paired fins at high speed, narrow caudal peduncle, lunate tail fins
                                    streamlined shape
    Flounder - bottom dwelling flatfish. Young have eyes on both sides of the head. Eyes migrate as they
                        develop , to one side. Flounder rapidly change color to match their back ground.
    Fresh water eels - catadromous fish. Migrate from American east coast  to breed at depths in the Sargasso sea
    Pacific salmon species - Anadromous fish. Mature at sea, home to native stream to spawn and die.
                                        Exhibit imprinting on  the chemical smell of their native stream.
    Sea Basses - all show sex reversal
    Parrot fish - show three sexes: male, female, and supermale
    Megalodon - extremely large ancestral shark thought to be related to modern Great Whites
    Hagfish and Marine Lamprey - both agnathans and similar to early, jawless, ancestral fish.
    Barracuda - lurk and lunge predator