Vertebrate Zoology; Teleost Feeding and Reproduction (4/3)

There is a vast diversity of reproductive strategies across animal groups, notably in teleosts (a large group of fish).
The lecturer expresses excitement about the topic of reproductive approaches and the intricate details involved.

The discussion starts with feeding modes in fishes and their positions in the food web.
- Piscivores: Fish that primarily eat other fish.
- Invertebrate feeders: Fish that feed on invertebrates.
- Different types include omnivores (generalist predators) and those targeting specific prey.
- Examples of predator types:
- Omnivores: A broader range of diet.
- Specific Predators: Such as smallmouth bass, which exhibit complex feeding behaviors including rehandling prey like crayfish.
Smallmouth bass example:
- Snorkeling observations of smallmouth bass catching crayfish during transects.
- Video example of a crayfish being captured, manipulated, and eaten by a smallmouth bass.
- Importance of determining feeding strategies to facilitate successful prey capture, such as positioning prey tail-first.

Brown Trout: Another example where some fish catch terrestrial prey as well.
Arowana: Known for its predatory behavior in flooded forests, gaining access to prey in trees during floods.
Coho Salmon Smolt: Exhibit dash and grab feeding behaviors, looking for aquatic insects and invertebrates.
- Drift feeding: Waiting for food items to drift by.
- Terrestrial insects falling into water serve as an energy subsidy from the terrestrial environment.
- Predatory fishes also exploit other animals, such as mice and ducks crossing water bodies.

Herbivores: Simpler feeding mechanisms mainly targeting aquatic plants and protists.
- Specialized gut bacteria help digest cellulose and lignin, enabling effective feeding on plant materials.
Examples of Herbivores:
- White amur or grass carp: Known for consuming extensive plant matter in ponds.
- Notably aggressive feeders and can affect entire aquatic ecosystems when uncontrolled.
Feeding Mechanism:
- Grass carp’s jaw structure allows capturing and breaking down various forms of aquatic vegetation.

Algivores: Fish that specifically feed on algae, illustrated by stone rollers and aquarium species like Placostomus.
- Scraping structures in their mouths are specialized for removing algae from surfaces.
Xylophagus: Fish feeding on dead wood; have specialized teeth to scrape the wood effectively.
- Some species possess gut bacteria to aid in digesting tough plant materials.

Parasitic fish may feed on hosts in various ways, including:
- Feeding on blood (e.g., snub-nosed eel attaches to gills and may invade deeper into the host).
- Candiru fish: Prey on other fishes' gills and also have notorious tales regarding their interaction with humans involving urination in water.
Unique Characteristics:
- Some parasites are specialized to only feed on certain parts of their host, like scales or eyeballs without consuming the host entirely.

Wimple Piranhas: Known for their specialized feeding behaviors that target fish scales.
- Adapted structures allow them to feed efficiently without causing fatal harm to the host fish.

Teleosts show unparalleled diversity in reproductive strategies compared to other animal groups.
Following researcher Charles Breager's principles:
- Focus on parental care, reproductive habitats, and energy use influences reproductive strategies.
Nongarters: Fish that provide no parental care; leave after spawning.
- Spawning methods include:
- Broadcast Spawners: Release eggs and sperm into the water during large spawning aggregations.
  - Example: Walleye can utilize this method effectively without mate choice.
  - Pelagic and benthic spawning explained.
Spawning Process:
- Fish come together in large numbers, creating visually spectacular events known as "breeding balls." This can attract predators like whale sharks who've developed behaviors around these spawning events.

Mention of Gladden Spit Marine Reserve as a success story in managing fisheries to protect spawning areas, demonstrating the effectiveness of conservation measures in balancing fish populations and ecosystems.
- Increased tourism due to healthy fish populations drawing in ecotourism opportunities, highlighting the balance between preservation and local economic gain.