Feeding Mechanisms in Various Fish Species

1. Overview & Comparison of Feeding Mechanisms in Various Fish Species Biology of Fishes October 18, 2012

2. Fish Species • Hypostomus plecostomus (algae-eater) Teleostei, Loricariidae omnivore • Amphilophus citrinellus (red devil cichlid) Teleostei, Cichlidae carnivore • Lepisosteus osseus (longnose gar) Holostei, Lepisosteidae piscivore • Esox americanus vermiculatus (grass pickerel) Teleostei, Esocidae piscivore • Protopterus annectens (West African lungfish) Dipnoi, Protopteridae omnivore

3. Prey Item Carassiusauratus

4. Hypostomus plecostomus • Naturally occurs in South American rivers, feeding on plant material • Sucker mouth with rasping teeth & bony structures • Primarily herbivorous (mainly algae) but will scavenge on dead animal matter • Ventrally flattened for bottom feeding

5. Hypostomus plecostomus • Scavenging behavior

6. Amphilophus citrinellus • Naturally occurs in Central American lakes • More ‘typical’ laterally compressed body • Mouth & jaw structure mobile, can be extended to create suction for feeding and nest building • Carnivorous, feeds primarily on snails, insects, smaller fishes

7. Amphilophus citrinellus • Teeth and bony ridge allow A. citrinellus to crush/eat snails, insects, and fish • Complex mouth morphology allows ‘extension’ to generate suction in capturing prey fish and in moving substrate for nest building

8. Amphilophus citrinellus • Prey capture utilizing extension of mouth to create suction

9. Amphilophus citrinellus • Prey capture utilizing extension of mouth to create suction

10. Amphilophus citrinellus • Mouth morphology also used to move substrate for nest building

11. Lepisosteus osseus • Naturally occurs in North American lakes and rivers • Elongate, more ancestral body structure • Skull & jaw structure fused, less mobile (compared to teleosts like A. citrinellus) • Primarily piscivorous

12. Lepisosteus osseus • Elongate (but less mobile) jaw structure and numerous teeth allow capture & grasping of prey fish • L. osseus hunts prey fishes as individuals or in schools; primarily utilizes ‘Pattern B’ attack • L. osseus uses both active hunting and lie and wait tactics

13. Lepisosteus osseus

14. Lepisosteus osseus

15. Lepisosteus osseus

16. Esox americanus (vermiculatus) • Naturally occurs in North American lakes and rivers • Elongate body structure • Jaws with mobile maxilla, utilize suction and grasping • Primarily piscivorous

17. Esox americanus • E. americanus utilizes ‘lie & wait’ strategy • Camouflage enhances ambush tactics

18. Esox americanus

19. Protopterus annectens • Native to West African lake & river systems • One of the ‘most primitive’ fishes • Obligate air-breathers • Lobed fins for locomotion & prey detection • Tooth plates

20. Protopterus annectens

21. Protopterus annectens

22. Conclusions & Discussion • Fishes of various body types and mouth morphologies can utilize different tactics to consume the same type of prey • Which species utilize the different foraging patterns (time minimizing, energy maximizing)? • Which species’ tactics have the most handling time? • Does one type of feeding behavior seem more successful than the others (of the six species observed)?

23. Questions?