Common Slugs, Snails, and Flatworms

Semi-Slug (Parmarion martensi)

Full grown adults can get up to 2 inches
Various shades of mottled grey
Hump on the back
Piece of shell on the hump

semi slug on ti plant — Adult Semi-slug

adult and immature semi slugs. showing different sizes of semi slugs — Adult Semi-slug

Giant African Snail (Achatina fulica)

Full grown adults can get up to 8 inches long and 5 inches in diameter
Shells are brownish with darker brown lengthwise stripes
Seven to nine whorls, including a swollen long body whorl, and cover at least half the length of the snail.

adult african snail in grass — Adult Giant African Snail

immature african snail — Adult Giant African Snail

Cuban Slug (Veronicella cubensis)

Various shades of brown
Two black/dark brown stripes along body, or no stripes. Stripes can be broken making them look spotty
Thin light colored line down the middle of the body
Adults can be around 2-3 inches long

cuban slug that has a mottled coloring rather than stripes — Cuban slug with no stripe

cuban slig with distinctive pair of black stripes — Cuban slug with no stripe

Black Slug (Veronicella leydigi)

Black with a thin yellow stripe
Body appears leathery

black slug on root ball — Black Slug
Photo by: Scot Nelson

black slug feeding on produce — Black Slug
Photo by: Scot Nelson

Grey Field Slug (Deroceras reticulatum)

1 – 3 inches long
Creme or grey colored
Back half of the slug has grooves
Can have dark grey/brown speckles

Grey Field Slug, creme colored, no speckles — Grey Field Slug, creme colored, no speckles
Wikimedia Commons

grey field slug, grey with speckles — Grey Field Slug, creme colored, no speckles
Wikimedia Commons

Meghimatium bilineatum

Off white/light brown
2-3 inches long
Faint lines along the back

Meghimatium bilineatum next to ruler — Meghimatium bilineatum

Meghimatium bilineatum with finger for size reference — Meghimatium bilineatum

Hammerhead flatworm (Bipalium species)

1- 3+ inches long
prominent wider shovel-shaped head
May have one or several longitudinal stripes

close-up photo of a brown flatworm with a darker stripe on a gray background — Hammerhead worm
Photo By: Bart Everson/ Wikimedia Commons

a close up photo of a brown flatworm with two dark stripes on a green leaf — Hammerhead worm
Photo By: Bart Everson/ Wikimedia Commons

New Guinea Flatworm (Platydemus manokwari)

1.5 – 5 inches long
shiny and dark brown with a longitudinal tan stripe
underside is lighter tan or pink colored

a brown flatworm crawling along red dirt and a root — New Guinea Flatworm
Photo By: Shinji Sugiura/ Wikimedia Commons

a closeup photo of a brown flatworm on a board — New Guinea Flatworm
Photo By: Shinji Sugiura/ Wikimedia Commons