Adaptations of Organisms Adaptations of Organisms to Lotic Habitatsto Lotic Habitats

By:By:

Victoria LewisVictoria Lewis

Natalie JacksonNatalie Jackson

Nancy JonesNancy Jones

Ruth Starr-KeddleRuth Starr-Keddle

IntroductionIntroduction

In lotic systems, the velocity of flowing In lotic systems, the velocity of flowing water is a major influence on:water is a major influence on:

substrate type, with boulders deposited in fast-flow substrate type, with boulders deposited in fast-flow and fine sediments in slow-flow areas,and fine sediments in slow-flow areas,

transport of particles, either as a food source for transport of particles, either as a food source for filter-feeders or, during peak flows, as scouring filter-feeders or, during peak flows, as scouring agents,agents,

maintenance of high levels of dissolved oxygen.maintenance of high levels of dissolved oxygen.

A stream or river contains A stream or river contains heterogeneous micro-habitats heterogeneous micro-habitats interspersed with;interspersed with;

riffles,riffles,deeper natural pools,deeper natural pools,erosion of banks,erosion of banks,sediments deposited,sediments deposited,areas of unstable, shifting sandy substrates.areas of unstable, shifting sandy substrates.

Adaptations Of Aquatic Adaptations Of Aquatic Plants To Lotic HabitatsPlants To Lotic Habitats Leaves & stems within, or floating on Water.Leaves & stems within, or floating on Water.

Upper leaves or shoots able to grow above the Upper leaves or shoots able to grow above the water, lower ones able to grow submergedwater, lower ones able to grow submerged.. Tall monocotyledons- Grasses, sedges & rushesTall monocotyledons- Grasses, sedges & rushes Short dicotyledons-the fringing herbs-typically found fringing Short dicotyledons-the fringing herbs-typically found fringing

the sides of small brooksthe sides of small brooks Short monocotyledons, mainly grasses, again frequently at Short monocotyledons, mainly grasses, again frequently at

the sides of brooksthe sides of brooks

A very few tall dicotyledonsA very few tall dicotyledons

Bank plants growing above normal water level, Bank plants growing above normal water level, flooded after heavy rain.flooded after heavy rain.

Adaptations of Insects to Adaptations of Insects to Lotic HabitatsLotic Habitats

Morphological AdaptationsMorphological AdaptationsDorsoventral FlatteningDorsoventral FlatteningCase ConstructionCase ConstructionSuckersSuckersSilk NetsSilk NetsSizeSize

Behavioural AdaptationsBehavioural AdaptationsUse of DriftUse of DriftBurrowingBurrowing

Morphological AdaptationsMorphological Adaptations

Dorsoventral FlatteningDorsoventral FlatteningAllows the organism to stay close to Allows the organism to stay close to

the substrate where there is a layer of the substrate where there is a layer of still water. An example of this is the still water. An example of this is the Water Penny.Water Penny.

Case ConstructionCase ConstructionA variety of case shapes made by A variety of case shapes made by

caddis fly larvae assist in streamlining caddis fly larvae assist in streamlining and act as a ballast.and act as a ballast.

Morphological AdaptationsMorphological Adaptations

SuckersSuckersAllows the insect to stick to quite Allows the insect to stick to quite

smooth exposed surfaces such as rock smooth exposed surfaces such as rock faces or in waterfalls, some Diptera faces or in waterfalls, some Diptera larvae use this.larvae use this.

Silk NetsSilk NetsUsed to maintain position in flow. Used to maintain position in flow.

Blackfly larvae attach their claws to a Blackfly larvae attach their claws to a silk pad attached to a rock.silk pad attached to a rock.

Morphological AdaptationsMorphological Adaptations

SizeSizeBeneficial to be smaller and have Beneficial to be smaller and have

flexible bodies, allowing them to live flexible bodies, allowing them to live in the bed (benthos) of the stream in the bed (benthos) of the stream between the boulders, stones and between the boulders, stones and pebbles.pebbles.

Behavioural AdaptationsBehavioural Adaptations

DriftDriftA drifting stategy can be used to A drifting stategy can be used to

move from an unsuitable location. move from an unsuitable location. Some insects such as Baetis follow a Some insects such as Baetis follow a diurnal periodic pattern of drift. diurnal periodic pattern of drift. ‘Catastrophic Drift’ is used by some ‘Catastrophic Drift’ is used by some as a response to physical disturbance.as a response to physical disturbance.

Behavioural AdaptationsBehavioural Adaptations

BurrowingBurrowingInsects will burrow deep into the Insects will burrow deep into the

substrate (the hyporheic zone) where substrate (the hyporheic zone) where they can avoid fluctuations in the they can avoid fluctuations in the environment.environment.

Adaptations of Vertebrates to Adaptations of Vertebrates to Lotic HabitatsLotic Habitats

All 5 phyla possess species adapted to All 5 phyla possess species adapted to life in lotic habitats;fish, amphibians, life in lotic habitats;fish, amphibians, reptiles, birds, and mammals.reptiles, birds, and mammals.

Streamlined body shapes to reduce Streamlined body shapes to reduce friction in water.friction in water.

Some more specialised adaptations in Some more specialised adaptations in life history, physiology and morphology.life history, physiology and morphology.

Adaptations of FishAdaptations of Fish

8,500 freshwater species.8,500 freshwater species. Salmonoids & Lampreys; DIAROMOUSSalmonoids & Lampreys; DIAROMOUS

Lampreys larval stage; AMOCOETELampreys larval stage; AMOCOETESalmonoids can vary their growth ratesSalmonoids can vary their growth rates

CATADROMOUS, e.g. eelsCATADROMOUS, e.g. eels DIADROMOUS GLOBOID; larval stage at DIADROMOUS GLOBOID; larval stage at

sea.sea.

Adaptations of AmphibiansAdaptations of Amphibians

2 common families; URODELA 2 common families; URODELA (salamanders & newts), ANURA (frogs & (salamanders & newts), ANURA (frogs & toads).toads).

Eggs laid in freshwater.Eggs laid in freshwater. Larval stage possess gills, but also use Larval stage possess gills, but also use

skin for gaseous exchange.skin for gaseous exchange. Adults possess lungs but still use their Adults possess lungs but still use their

skin as well for gaseous exchange.skin as well for gaseous exchange.

Adaptations of ReptilesAdaptations of Reptiles

Some species of snake and turtle are Some species of snake and turtle are found in lotic habitats.found in lotic habitats.

Crocodiles;Crocodiles;Eyes, nostrils & ears on top of head.Eyes, nostrils & ears on top of head.NICTITATING membrane to cover eyes.NICTITATING membrane to cover eyes.Valves to close ears & nostrils.Valves to close ears & nostrils.Long thin body with short legs good for Long thin body with short legs good for

sinuous swimming movements.sinuous swimming movements.

Adaptations of BirdsAdaptations of Birds

Dippers;Dippers;Dense, waterproof feathers.Dense, waterproof feathers.Nasal flaps.Nasal flaps.Wings used like flippers when in water.Wings used like flippers when in water.NICTITATING membrane.NICTITATING membrane.

Ducks;Ducks;Few species are confined to a lotic habitat.Few species are confined to a lotic habitat.Harlequin duck, truly lotic.Harlequin duck, truly lotic.

Adaptations of MammalsAdaptations of Mammals

Few aquatic species exclusively reside Few aquatic species exclusively reside in lotic habitats.in lotic habitats.

Otters; lutra (genus)Otters; lutra (genus)Streamlined body shape.Streamlined body shape.Broad flat tail involved in sinuous swimming Broad flat tail involved in sinuous swimming

movements.movements.Short dense fur impermeable to water.Short dense fur impermeable to water.Large lung capacity allowing long dives.Large lung capacity allowing long dives.Partially webbed feet for swimming.Partially webbed feet for swimming.

Platypus; Platypus; Webbed feet, short fur, Lacks external ears.Webbed feet, short fur, Lacks external ears.Feeds on bethic invertebrates.Feeds on bethic invertebrates.Bill covered with soft skin possessing many Bill covered with soft skin possessing many

electrosensors.electrosensors.Broad flat tail used as rudder when diving & surfacingBroad flat tail used as rudder when diving & surfacing

River Dolphin;River Dolphin;only mammal confined to lotic habitats.only mammal confined to lotic habitats.Poor vision.Poor vision.Narrow, very sensitive sonic beam for location of food Narrow, very sensitive sonic beam for location of food

& obstacles.& obstacles.Smaller body size than marine dolphin.Smaller body size than marine dolphin.

ConclusionConclusion

Some plants and invertebrates have Some plants and invertebrates have specific adaptations to the lotic specific adaptations to the lotic environment, and vertebrates tend to be environment, and vertebrates tend to be suited to an aquatic environment.suited to an aquatic environment.

All are linked together in the lotic All are linked together in the lotic environment, ie. Submerged plants environment, ie. Submerged plants provide egg-laying sites for invertebrates provide egg-laying sites for invertebrates and fish, and lurking sites for predators.and fish, and lurking sites for predators.