BIOL 1108 1st EditionLecture 12Outline of Last Lecture I. LocomotionII. Feeding III. Reproduction and Development Outline of Current Lecture I. Oviparous/ Viviparous/ OvoviparitySpeciesII. Development III. Sensory Systems Current LectureI. Oviparous/ Viviparous/ OvoviparitySpecies- Oviparous: “egg-laying”o Eggs are layed outside the body and nourishment comes from yolk in the eggo Most fish have a larval stage - Viviparous: “live-bearing”o Young develop inside the mother and get nourishment from the mother o Nourishment from fish “placental” connection Secretions in the reproductive tract Nutritive eggs- additional eggs are food for fertilized eggs o Skip the larval stage o Typically follow internal fertilization- Ovoviparity: botho Eggs are produced but are retained inside the female until around the time of hatching o Nourishment from the egg yolkII. Development- Larval stage: starts when young switch from yolk to an external food source- Juvenile stage: miniature version of the adult form These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Deviationso Flatfishes- flounders, halibut, sole young are bilaterally symmetrical (eyes are not on one side of head) Asymmetric development o Smoltification of Anadromous Salmonids Migrating individuals from the Salmonidae family Egg Larvae Fry ParrSmolt Adult Transition from freshwater to saltwater (changes in environmentalconditions) - Adult stage: attainment of sexual maturity (age depends)III. Sensory Systems - Gain information from the environment o Hearing- range varies Otoliths Gas bladder o Lateral Line System- detects vibrations and changes in water pressure Consists of neuromast cells along the side of the fish’s body Provides spatial awareness Allows them to navigate in space o Vision Eye Structure- Cornea- Iris- Pupil - Lens held by ligaments - Retina where photoreceptors are located - Optic nerve Fish have round lens whereas terrestrial vertebrates have more elliptical lens - Effects the focusing of light through the eye - Very little refraction difference in aquatic environment 2 types of photoreceptors- Rods- light receptiono More rods in nocturnal fish- Cones- color reception o More cones in coral Tapetumlucidum- layer of guanine crystals behind the receptor layer of the retina - Reflect light o Smell- olfaction Nasal sacs- contain olfactory receptors that detect chemical cues in the water - Complexity depends on feeding habits of
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