sea life

Exam Announcement

  • First exam on Thursday.

  • Review session scheduled for the day before the exam.

  • Might provide new information for the second exam to be noted separately.

Material Review

  • Last session focused on the topic of symbiosis.

  • Different types of symbiotic relationships include:

    • Mutualism: Both organisms benefit.

    • Commensalism: One organism benefits while the other is unaffected.

    • Parasitism: One organism benefits at the expense of another.

    • Equalism: Organism lives inside another (e.g., pearl fish with loggerhead sponge).

Symbiotic Examples Discussed

  • Commensal relationships examples:

    • Crabs and clams.

    • Remoras hitching rides on larger fish.

  • Mutualism includes:

    • Zooxanthellae and corals:

    • Zooxanthellae provide oxygen and nutrients to corals while receiving waste products.

    • Sea anemones and clownfish:

    • Clownfish clean area around anemones, benefiting both.

Interesting Research Discussion

  • Meeting insights from Palm Beach County Environmental Resource Management:

    • Discovery of 2,500 unique great white sharks off local waters, previously not thought to inhabit due to warm water.

Types of Symbiosis

  1. Mutualism:

    • Benefits both parties involved.

    • Examples revisit previous encounters like clownfish and anemones as well as cleaner fish and clientele fish.

  2. Commensalism:

    • One benefits; the other remains neutral.

    • Remoras on turtles/divers and fish using urchins for protection.

  3. Parasitism:

    • One benefits while the other suffers.

    • Ectoparasites (outside) vs. endoparasites (inside) discussed.

Unique Parasitic Stories

  • Somnothia fish: Loses tongue, gains copepod (an ectoparasite that becomes an endoparasite).

  • Lymphocystis: Viral ectoparasite affecting aquarium fish, resulting in white bumps on their scales.

Rules of thumb discussed for avoiding parasites in seafood:

  • Choose smaller fish over larger ones as bigger fish are likely to have accumulated parasites.

Cleaning Symbiosis

  • Mutualistic relationship where one species cleans another.

  • Organisms, like cleaner shrimp, enjoy feeding off parasites while their hosts gain cleanliness.

Transition to Next Topic: Salinity and Osmoregulation

  • Acknowledgment of transitioning from symbiotic relationships to salinity and osmoregulation, which will not be on the upcoming exam but will be on the second exam.

Introduction to Salinity and Osmoregulation

  • Salinity:

    • Refers to saltiness of water.

    • Saline solution is less salty than ocean water.

  • Osmoregulation:

    • The process by which organisms regulate water and salt in their bodies.

    • Important for maintaining cellular integrity and overall health.

Refractometer Explanation

  • A device used to measure salinity by bending light through a water sample to display a shadow on a scale.

  • Normal seawater salinity is about 35-36 parts per thousand (PPT).

Fresh Water vs. Salt Water Comparison

  • Freshwater is typically near 0 PPT, and saltwater around 36 PPT.

  • Estuaries are where saltwater and freshwater mix (critical ecosystems).

Importance of Salinity

  • Affects density and buoyancy of water, necessitating specific adaptations for marine life.

  • Organisms must adapt via osmoregulation to maintain homeostasis in varying salinity levels.

Diffusion vs. Osmosis

  • Diffusion:

    • General movement of solutes from high to low concentration across a membrane until equilibrium is reached.

  • Osmosis:

    • Movement of water through a semi-permeable membrane toward a higher solute concentration, affecting cell size and integrity.

Terms of Osmotic Pressure

  • Hyperosmotic: Higher solute concentration.

  • Hypoosmotic: Lower solute concentration.

  • Isosmotic: Equal solute concentration on both sides of the membrane.

Examples of Different Organisms

  • Invertebrates (e.g., shrimp): Tend to regulate body salt concentration to match environments.

  • Marine Fish (e.g., dolphin fish): Hypoosmotic relative to ocean, constantly drink seawater and excrete excess salt.

  • Sharks: Hyperosmotic due to urea storage, allowing them to thrive in varying salinity environments.

Recap on Exam Details

  • Exam consists of approximately 45-50 questions.

  • Multiple choice format on scantrons; specific preparation for parts previously discussed such as salinity, symbiosis, physical oceanography, etc.

Study Recommendations and Final Thoughts

  • Emphasis on understanding key principles over rote memorization.

  • Questions to reflect on practical connections made in lectures to real-world phenomena observed in ocean studies.

  • Clarifications and assistance available through questions regarding the exam format and materials.