Shells from Sonora state, west Mexico

Here are some of the shells found in the Guaymas area, taken in the field and while the mollusks were still living in a small aquarium. I used an Olympus Camedia model D340R digital camera and on a later trip a Nikon Coolpix2100. I enhanced the photos in Photoshop.

The next scheduled trip to Guaymas is in November of 2005.
Oliva spicata

An active shell often found at the surf line popping out of the sand when the tide begins to come in.


A group of shells from one of the beach areas, found in sand between shore and a sand bar at low tide.


More of the beach shells from the same area.

Hexaplex erythrostomus, "Pink-Mouthed Murex"

These shells are collected by wading from boats in shell beds far from the beach. The fishermen wear waders and bring up boxes full of shells for sale to locals as food. There are huge piles of empty shells near the beaches and occasionally you find live ones on the beach - possibly escapees.

Hexaplex erythrostomus, "Pink-Mouthed Murex"

A small specimen found "popping" out of the sand when the tide began coming in.

"Cup-and-Saucer Limpets"

Any hard surface in a mud flat makes a mini-reef. These shells are living on a tire.

Trachycardium panamense

This cockle shell is found in sandy and muddy areas.

Columbella aureomexicana

These active shells have a bright orange aperture.

Diodora digueti

Limpets are usually on rocks, where they can protect their soft parts, since the shell is open on the bottom. This species is found on the underside of rocks during the day.

Hormospira maculosa

Turridae are usually not gregarious, but this species is. We find it popping out of the sand when the tide starts to come in.

Melongena patula

I found this species alive for the first time in 2004, in a sandy bay. It can reach ten inches in length.

Melongena patula

A smaller specimen performed in the aquarium.

Morula ferruginosa

A common Muricid found under rocks.

Nassarius versicolor

This quarter-inch shell looks huge in the picture. It is a scavenger, keeping the bay clean by eating the garbage.

Natica chemnitzii

A very active snail that lives in sandy bays.

Polinices recluzianus

Common in sandy bays, where it eats bivalves. These animals make trails in the sand and are very active...

Polinices recluzianus fact, so active I took lots of pictures of it.

Olivella dama

Another active animal living in the intertidal sand.

Sea Hares

These animals are shell-less molluscs. They come together from time to time to lay eggs. Each animal is both male and female (hermaphroditic) and they fertilize one another, then lay eggs. The slime they secrete to ease their movement through the mud also gathers mud so they are camouflaged.

Sea Hare

Another species of shell-less mollusc. It looks just like the algae in the bay.

Haminoea species

Related to the sea hares, these animals are too big for their shells. They also secrete lots of slime. The shell is very delicate and translucent.

Oxynoe panamensis

Another sea hare-like animmal, this green slug has a small internal shell. Living, it looks like a piece of algae and is usually found on sea grasses.


"It's a cowry!"

Cypraea annettae

Cowries are found under rocks. These came from intertidal rocks at low tide.

Cypraea annettae

The living animal is even more spectacular than the shell, with its mantle very colorful and studded with papillae.

Conus princeps

Found under rocks in an intertidal cove.

Turbo fluctuosus

This active animal lives under rocks. The operculum is used in shellcraft. Villagers gather these shells for dinner.

Astraea unguis

This star shell was covered with algae and other growths, making it difficult to see in its rocky environment.

Astraea unguis

Here you can see the animal as it reaches out to right itself.

Thais speciosa

Another rock dweller (in fact, called a "Rock Shell").

Solenosteira macrospira

Found in sandy and muddy areas, very common.

Eupleura muriciformis

This animal drills a hole in other shells to get at the meat. It lives in sandy areas.

Agaronia testacea

Living at the surf zone on beaches, this active animal can extend its foot quickly and far, in order to right itself when washed out of the sand. In fact, using its spread-out foot, it can actually swim.

Parametaria dupontii/I>

Though it looks like a cone, this is a dove-shell that lives under intertidal rocks.

Tegula rugosa

These active animals have, besides their eyestalks, several long tentacles which help them sense their surroundings.

Another view of Tegula rugosa
Terebra species

Little of the animals of these shells is exposed. Their long, slender shells make easy movement through sand.

Theodoxus luteofasciatus

You can find these shells in any color of the rainbow and usually at least two colors. They live intertidally in large colonies, actively crawling about looking for food. Size is up to one-quarter inch or so.