Overview & Comparison of Overview & Comparison of Feeding Mechanisms in Feeding Mechanisms in

Various Fish SpeciesVarious Fish SpeciesBiology of FishesBiology of FishesOctober 18, 2012October 18, 2012

Fish SpeciesFish Species Hypostomus plecostomusHypostomus plecostomus (algae-eater) (algae-eater)

Teleostei, LoricariidaeTeleostei, Loricariidaeomnivoreomnivore

Amphilophus citrinellusAmphilophus citrinellus (red devil cichlid) (red devil cichlid)Teleostei, CichlidaeTeleostei, Cichlidae

carnivorecarnivore Lepisosteus osseusLepisosteus osseus (longnose gar) (longnose gar)

Holostei, LepisosteidaeHolostei, Lepisosteidaepiscivorepiscivore

Esox americanus vermiculatusEsox americanus vermiculatus (grass pickerel) (grass pickerel)Teleostei, EsocidaeTeleostei, Esocidae

piscivorepiscivore Protopterus annectensProtopterus annectens (West African lungfish) (West African lungfish)

Dipnoi, ProtopteridaeDipnoi, Protopteridaeomnivoreomnivore

Prey ItemPrey Item

Carassius auratusCarassius auratus

Hypostomus plecostomusHypostomus plecostomus

Naturally occurs in South Naturally occurs in South American rivers, feeding on American rivers, feeding on plant materialplant material

Sucker mouth with rasping Sucker mouth with rasping teeth & bony structuresteeth & bony structures

Primarily herbivorous Primarily herbivorous (mainly algae) but will (mainly algae) but will scavenge on dead animal scavenge on dead animal mattermatter

Ventrally flattened for Ventrally flattened for bottom feedingbottom feeding

Hypostomus plecostomusHypostomus plecostomus Scavenging behaviorScavenging behavior

Amphilophus citrinellusAmphilophus citrinellus Naturally occurs in Central Naturally occurs in Central

American lakes American lakes More More ‘‘typicaltypical’’ laterally laterally

compressed bodycompressed body Mouth & jaw structure Mouth & jaw structure

mobile, can be extended to mobile, can be extended to create suction for feeding create suction for feeding and nest buildingand nest building

Carnivorous, feeds primarily Carnivorous, feeds primarily on snails, insects, smaller on snails, insects, smaller fishesfishes

Amphilophus citrinellusAmphilophus citrinellus Teeth and bony ridge Teeth and bony ridge

allow allow A. citrinellusA. citrinellus to to crush/eat snails, crush/eat snails, insects, and fishinsects, and fish

Complex mouth Complex mouth morphology allows morphology allows ‘‘extensionextension’’ to generate to generate suction in capturing suction in capturing prey fish and in moving prey fish and in moving substrate for nest substrate for nest buildingbuilding

Amphilophus citrinellusAmphilophus citrinellus Prey capture Prey capture

utilizing utilizing extension of extension of mouth to create mouth to create suctionsuction

Amphilophus citrinellusAmphilophus citrinellus Prey capture utilizing extension Prey capture utilizing extension

of mouth to create suctionof mouth to create suction

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

Lepisosteus osseusLepisosteus osseus Naturally occurs in North American lakes and riversNaturally occurs in North American lakes and rivers Elongate, more ancestral body structureElongate, more ancestral body structure Skull & jaw structure fused, less mobile (compared to Skull & jaw structure fused, less mobile (compared to

teleosts like teleosts like A. citrinellusA. citrinellus)) Primarily piscivorousPrimarily piscivorous

Lepisosteus osseusLepisosteus osseus Elongate (but less mobile) jaw structure and numerous Elongate (but less mobile) jaw structure and numerous

teeth allow capture & grasping of prey fishteeth allow capture & grasping of prey fish L. osseusL. osseus hunts prey fishes as individuals or in schools; hunts prey fishes as individuals or in schools;

primarily utilizes primarily utilizes ‘‘Pattern BPattern B’’ attack attack L. osseusL. osseus uses both active hunting and lie and wait uses both active hunting and lie and wait

tacticstactics

Lepisosteus osseusLepisosteus osseus

Lepisosteus osseusLepisosteus osseus

Lepisosteus osseusLepisosteus osseus

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

Esox americanusEsox americanus

E. americanus utilizes ‘lie & wait’ strategy

Camouflage enhances ambush tactics

Esox americanusEsox americanus

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

Protopterus annectensProtopterus annectens

Protopterus annectensProtopterus annectens

Conclusions & DiscussionConclusions & Discussion Fishes of various body types and mouth Fishes of various body types and mouth

morphologies can utilize different tactics to consume morphologies can utilize different tactics to consume the same type of preythe same type of prey

Which species utilize the different foraging patterns Which species utilize the different foraging patterns (time minimizing, energy maximizing)?(time minimizing, energy maximizing)?

Which speciesWhich species’’ tactics have the most handling time? tactics have the most handling time? Does one type of feeding behavior seem more Does one type of feeding behavior seem more

successful than the others (of the six species successful than the others (of the six species observed)? observed)?

Questions?Questions?