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

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

Prey Item Carassius auratus

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

Hypostomus plecostomus Scavenging behavior Scavenging behavior

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

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

Amphilophus citrinellus Prey capture utilizing extension of mouth to create suction Prey capture utilizing extension of mouth to create suction

Amphilophus citrinellus Prey capture utilizing extension of mouth to create suction Prey capture utilizing extension of mouth to create suction

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

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

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

Lepisosteus osseus

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

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

Esox americanus

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

Protopterus annectens

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

Questions?