Immersing Corpses in Water

4/10/08

Overall Effects on Corpse

Decomposition generally retarded

Decomp begins in head region

Skin of hands and feet

Livor mortis may not appear

Bloating

Overall Effects on Corpse

Finger and toenails easily detachable

Skeletonization

Faunal Associates

Ectoparasites

Fleas

Body lice

Carrion Community Associates

Pig carcass study by Payne

Stage one: submerged fresh

Bloat

Aquatic Insects

Hydrophilid Beetles

Coleoptera: Hydrophilidae

Water scavenger beetles

284 species in North America

1-40 mm

Long palpi

Larvae predatory, adults scavengers

Hydropsychid Caddisflies

Trycoptera: Hydropsychidae

Water nymph

146 species in North America

Adults 6-19 mm

Larvae: streams and rivers

Feed on algae, diatoms, crustaceans, insects

Chironomid MidgesDiptera: Chironomidae

Non-biting midtes

700 species

1-10 mm

Resemble mosquitos

Larvae aquatic

Simulidae Larvae

Diptera: Simulidae

Black flies

Blood feeders

Small, black/grey

Larvae aquatic

Heptageniid Mayflies

Ephemeroptera: Heptageniidae

Mayflies

500 species

Clear wings, prominent venation

Nymps aquatic, flattened, streamlined

Carrion Community Associates

Stage two: submerged fresh

Early Floating

Exposed abdomen: eggs

Submerged portions still inhabited by organisms in stage one

Carrion Community Associates

Stage three: Floating Decay

Blowfly eggs hatch

Oviposition ceased by Day 3

Coleoptera

Silphids, Staphylinids, Histerids

Carrion Community Associates

Stage four: Bloated Deterioration

Many maggots, beetles

Most tissues gone

Carrion Community Associates

Stage five: Floating Remains

Few maggots

Histerid beetles

Small flies: Sphaerocerids, Phorids, Drosophilids, Psychodids

Stage ends when remains sink

Carrion Community Associates

Stage six: Sunken Remains

Decomp completed by bacteria and fungi

Postmortem Submersion Interval

Make use of organisms which attach themselves to substrate

Understand differences between moving and still water organisms

no purely sarophagous aquatic insects

Ecological Function

Food for invertebrates and fish

Shelter

Attract secondary scavengers

Substrate for producers

Substrate for grazers

Saltwater Submersion

Fauna almost completely different from fresh water

little studied

Barnacles

Shrimp, prawns, crabs

AnyQuestions?