LIVING JEWELS – But is that all? / MOLLUSK DIVERSITY/h1>
PANEL 1
LIVING JEWELS – But is that all?
MALACOLOGY noun – feminine
[Zoology] Branch of zoology that studies mollusks.
Etymology:
malakós + logia
Priberam Dictionary of the Portuguese Language
Greek: Soft, Tender. Refers to the idea of a mollusk.
PANEL 2 – MOLLUSK DIVERSITY
Mollusks are invertebrate animals with soft bodies but well-developed muscles. In other words, mollusks are very strong animals!
The phylum Mollusca is the second-largest animal group in terms of the number of species, and it is divided into 7 classes:
Gastropoda, Scaphopoda, Bivalvia, Cephalopoda, Monoplacophora, Aplacophora, and Polyplacophora.
The best-known classes are:
- Gastropoda – Animals that can live on land or in water, with or without a coiled shell.
- Bivalvia – Commonly known as oysters, mussels, scallops, and clams. They have a shell made of two parts called valves that protect their body – hence the name bivalves.
- Cephalopoda – Animals with a body made up of a head (cephalo), arms, and tentacles (poda), used for movement and feeding. Octopuses and squids belong to this group.
A slug is a slug, a snail lives on land, and aquatic snail lives in water
Slugs, snails, and freshwater snails are all gastropods.
Slugs have their organs spread throughout their soft, uncovered body, protected by a skin-like layer called a tegument.
Snails and freshwater snails, on the other hand, have their organs protected inside a shell. Both leave a slimy trail of mucus as they move.
Slug
Snail
Sea snail among sea urchins
Painting, flirting, and hiding
Octopuses and cuttlefish can change color not just to camouflage themselves when in danger or hunting, but also to attract mates. When threatened, they release a dark ink to distract their predators.
Octopus
Cuttlefish
Size does matter
There are microscopic mollusks, known as micromollusks, that are about the size of a grain of rice. On the other hand, the giant squid can reach up to 20 meters (65 feet) in length, and the bivalve Tridacna gigas, with a shell up to one meter (3 feet) wide, can weigh more than 250 kg (550 lbs). Because of its size, it was once used as a baptismal font.
Baptismal font
Small, but not fragile
Some mollusk species are less than four centimeters long. They have a very strong “foot” and produce sticky mucus that helps them cling tightly to rocks, even in strong ocean currents.
Gastropod commonly known as a limpet
Soft body, but iron armor!
The volcano snail is the only known animal that incorporates iron sulfide from the environment into its body. It lives over 2,000 meters deep in hydrothermal vents of the Indian Ocean, where temperatures can reach 350 to 400 °C (660 to 750 °F). This process creates a true iron armor that covers both its shell and its scaly foot.
Armored snails (Chrysomallon squamiferum)
I was born more than 500 years ago!
Bivalves are known for their longevity. According to scientists, this is due to their slow metabolism—caused by living in cold marine environments—along with genetic factors. In Iceland, in 2006, a specimen was collected that was 507 years old. It was nicknamed Ming.
Bivalve Arctica islandica, the same species as Ming