Mollusca
Classification: Mollusca are the second largest phylum of animals, and they represent about 23% of all marine life. That’s a lot of sea snail! They have a head and a foot which they use to move, these creatures often use their foot to move to travel and retrieve food. They also have a shell or an exoskeleton which they use to protect themselves from predators. This phylum have had 500 million years to evolve to where they are today so they have a good evolutionary advantage for their environment.
Diversity: They are divided into many classes including Aplacophora, Bivalvia and Cephalopoda. Some notable things about their species is that they use some organs for multiple purposes, like how that heart and the kidneys can play an important part in the reproductive system, which is something that is seen all across the phylum of Mollusca. They are found in the water and on dry ground, like slugs or snails, and in the water they include sea snails and nautiloid. Life History: They evolved in the Cambria period around 500 million years ago. They have sense moved out of the water and colonized the land as well. For the most part, they reproduce through external fertilization, although this is not the case with all of the members of the phylum. They are birthed from eggs and grow quickly to their adult stage. Of course the process is different as there are thousands of species that fall underneath the phylum. Ecological Roles: The role of these creatures’ varies as there is great diversity in the phylum. Some like snails and slugs consume crops on land which bothers famers. In the water they are often prey for larger predators, and are easy targets because they are slow moving. On the other hand, there are octopuses and giant squids which are known for attacking larger species making them the predators instead of prey. Human Interaction: Humans have used Mollusca for a long time, we have used them for dye in ancient time, most notably in Tyre. They can also attack humans which is an issue that people have had to deal with and they can also destroy aquaculture and farmers of those things have had to find way to keep them away from their crops/livestock. We also eat them, millions of tons of oysters are produced each year, along with some cultures that consume other Mollusca like shrimp or in isolated instances octopus. By Jared Cusack |