What are the 3 characteristics of cephalopods and of mollusks?
They’re made up of a body, a head and a foot. They have a muscular casing called a mantle which contains and protects their organs. They all have arms — at least eight of them — that are attached directly to their heads, but only some species also have tentacles.
What features are shared by all cephalopods?
Cephalopoda means “head foot” and this group has the most complex brain of any invertebrate. Cephalopods are characterized by a completely merged head and foot, with a ring of arms and/or tentacles surrounding the head. The arms, tentacles, and funnel are all derivatives of the foot.
What specific feature is only found in cephalopods?
The best-known feature of the cephalopods is the possession of arms and tentacles, eight or 10 in most forms but about 90 in Nautilus. Except for the nautilus, all living members of the class show great modification and reduction of the characteristic molluscan shell.
What are the 4 basic features of all mollusks?
All mollusks have a visceral mass, a mantle, and a foot. The visceral mass contains the digestive, excretory, and reproductive organs. The mantle is a covering. It may secrete a shell.
What features make cephalopods different from mollusks?
The most obvious difference between most cephalopods and other mollusks is the apparent lack of a shell. They are also the only cephalopods with four gills instead of two.) Cephalopods have a more developed nervous system than other mollusks. They also have very well developed eyesight that is used in finding prey.
What are three characteristics of cephalopods?
These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles (muscular hydrostats) modified from the рrimitive molluscan foot. Fishers sometimes call cephalopods “inkfish”, referring to their common ability to squirt ink.
What are the characteristics of cephalopods that are unique to them and make them distinct from other animals?
Which is not characteristics of cephalopods?
Excretory system – Cephalopods possess a single pair of large nephridia which produce nitrogenous waste and excrete it out from the body. Therefore, from the above discussion it has been clear that Sea squirt is not a cephalopod.
What is the special adaptation that cephalopods have for the mantle cavity?
In cephalopods, the mantle cavity has been adapted for use in locomotion. Water is expelled from the cavity through an organ called the siphon with great jet-propulsive force. This force allows some cephalopods to move with rapid speed.
What are distinctive features of mollusks?
Mollusks have a hard outer shell. There is a layer of tissue called the mantle between the shell and the body. Most mollusks have tentacles for feeding and sensing, and many have a muscular foot. Mollusks also have a coelom, a complete digestive system, and specialized organs for excretion.
What is a common feature of all mollusks?
WHAT FEATURES DO MOLLUSKS HAVE IN COMMON? As well as a shell, most mollusks have a muscular foot for creeping or burrowing. Some also have a head with sense organs. The soft body includes lungs or gills for breathing, and digestive and reproductive parts, all enclosed by a skinlike organ called the mantle.
What are the distinguishing features of cephalopods what features of cephalopods show their relation to other molluscs?
Characteristics: Cephalopods are mollusks, where the foot has developed into a set of arms or tentacles. Another common feature is their ability to squirt ink when threatened. Their body is symmetrical, i.e. the left and right side of the body is identical.
Are cephalopods mollusks?
Cephalopods are a group of swimming mollusks, including the living squid, octopus, and the chambered Nautilus. Although most living cephalopods have somewhat reduced shells, fossil shells were well developed. Cephalopod shells have evolved into many astonishing and beautiful forms,…
What is the body plan of a cephalopod?
The basic cephalopod body plan includes two eyes, a mantle, a funnel (also called a siphon), and at least eight arms. Some have hard, internal structures, like the cuttlebone in the cuttlefish and the pen in the squid, that evolved from the hard, outer shells of their ancestors, but in many octopuses the hard structure is completely lost.
What does a cephalopod shell look like?
Although most living cephalopods have somewhat reduced shells, fossil shells were well developed. Cephalopod shells have evolved into many astonishing and beautiful forms, exhibiting a variety of shapes, such as straight, slightly curved, crescent, and coiled.
Do cephalopods have a closed circulatory system?
Cephalopods are the only molluscs with a closed circulatory system. Coleoids have two gill hearts (also known as branchial hearts) that move blood through the capillaries of the gills. A single systemic heart then pumps the oxygenated blood through the rest of the body.