Updated: May 17, 2021
By Thomas Mesaglio
Take a stroll along any beach and it’s likely you’ll walk past forty, fifty, even a hundred species without even realising! Australia is home to an amazing diversity of marine molluscs, with thousands of species washing up onto our shores. Identifying molluscs from their shells can be tricky (especially when many specimens are broken, eroded or discoloured), so here are some photography tips to ensure you capture all the important features necessary for identification.
Gastropods are molluscs with one shell, including whelks, cowries and limpets. When photographing gastropods, always get a shot of the ventral (a) and dorsal (b) sides, as there are important features on both surfaces. The aperture (the opening where the snail emerges) is usually good to include as features like the outer lip or teeth can help differentiate between similar species. For specimens shaped like classic ‘snail shells’, try to get both a ventral shot (c) and a shot from directly beneath the shell (d); the area to the left of the aperture can be crucial for identification
Bivalves are molluscs with two shells, including oysters, mussels and clams, although most specimens are found as single, disarticulated shells. The golden rule for bivalves is to always take a photo of the outside (e) and the inside (f) of the shell! Perhaps the most important feature of bivalves is the hinge, which is where the two shells are joined together; this feature can tell you which family the specimen belongs to.
Knowing a shell’s size can be useful for identifications, but size isn’t always easily appreciable from photos. An easy way to provide a sense of scale is to photograph shells while holding them; remember to take photos of both sides!
If you’re lucky enough to find any live molluscs, always photograph both the shell and the animal itself. Always be careful when picking up live molluscs, as some species (cone shells) have potentially deadly venom. If you are unfamiliar with seashells, the best practice is to leave any live specimens where they are.
Before collecting any seashells, always check that it’s legal to do so. Many beaches are part of marine reserves or other protected areas where seashells (empty or otherwise) must not be collected. If in doubt, always take a photo and leave the shell where you found it. If you do collect specimens, try to limit the number you take; the more you collect, the fewer shells there are for the next beachcomber to appreciate, and the fewer homes there are for hermit crabs and other marine species which utilise empty shells as habitat. Most importantly, never collect live specimens!
Thomas Mesaglio is an avid NSW-based beachcomber obsessed with finding new seashells he’s never found before. If you have any tricky shells you want ID’ed, feel free to tag him (@thebeachcomber) on iNaturalist.