The key difference between cephalopods and gastropods is that cephalopods are exclusively marine animals, while the majority of gastropods are terrestrial, and some are from marine and freshwater.
Phylum Mollusca includes a group of soft-bodied invertebrates with bilateral symmetry. Molluscs have a shell. They also have a mantle, which is a thin layer of tissue covering their body organs. Moreover, they have a muscular foot underside of the body. The three groups of molluscs are gastropods, cephalopods, and bivalves. Cephalopods are marine animals. Gastropods are mainly terrestrial. Some gastropods are aquatic: salt and freshwater animals. Gastropods are the largest group, comprising more than 80% of the molluscs.
CONTENTS
1. Overview and Key Difference
2. What is Cephalopods
3. What is Gastropods
4. Similarities Between Cephalopods and Gastropods
5. Side by Side Comparison – Cephalopods vs Gastropods in Tabular Form
6. Summary
What are Cephalopods?
Cephalopods are a group of molluscs comprising of marine animals such as octopi, cuttlefish, and nautili, etc. They are strictly marine molluscs. Cephalopods are the most intelligent invertebrates. They have a highly developed nervous system with a complex brain. Moreover, they show rapid movements in the water. They can swim fast. Furthermore, they have a closed circulatory system.
Figure 01: Cephalopod
Cephalopods have a series of tentacles that circle the head. They are mostly predators that feed on fish, crustaceans, worms, and other molluscs. Their well-developed camera-type eyes help them catch prey. Some cephalopods such as octopus, squid, and cuttlefish species have the ability to change their colours.
What are Gastropods?
Gastropods are a group of molluscs that include snails, conchs, abalones, whelks, sea slugs, and garden slugs. It is the only group that contains terrestrial molluscs. Therefore, the majority of gastropods are terrestrial. Some gastropods live in marine water, while some other types live in freshwater. They live in a range of habitats. Gastropods such as snails have a coiled shell. But some gastropods like slugs do not have a shell.
Figure 02: Gastropod
Gastropods have a fairly well-developed head. They also have muscular foot. Though molluscs are described as bilateral symmetrical, gastropods are asymmetrical. Unlike cephalopods, gastropods have an open circulatory system. Some gastropods are herbivores, while some are carnivores. Terrestrial gastropods have lungs for respiration, while aquatic species have gills.
What are the Similarities Between Cephalopods and Gastropods?
- Cephalopods and gastropods are two classes belonging to the phylum Mollusca of Kingdom Animalia.
- They have coiled shells.
- Both groups include aquatic animals.
- They are invertebrates.
- Moreover, they have muscular foot.
What is the Difference Between Cephalopods and Gastropods?
Cephalopods are a group that includes exclusively marine molluscs. Gastropods are the largest group of molluscs containing terrestrial, marine, and freshwater animals. So, this is the key difference between cephalopods and gastropods. Cephalopods include squid, octopuses, cuttlefish, and chambered nautiluses while gastropods include snails, conchs, abalones, whelks, sea slugs, and garden slugs. Moreover, Cephalopods have a closed circulatory system, while gastropods have an open circulatory system. Thus, this is another difference between cephalopods and gastropods.
The below infographic tabulates the differences between cephalopods and gastropods in detail for side by side comparison.
Summary – Cephalopods vs Gastropods
Cephalopods and gastropods are two groups of molluscs. Cephalopods are found only in marine water. The majority of gastropods are terrestrial, while few are marine and freshwater animals. Cephalopods are the most intelligent vertebrates, and they move fast in the water. Gastropods are less intelligent, and they are slow-moving animals. Cephalopods have a closed circulatory system while gastropods have an open circulatory system. Thus, this summarizes the difference between cephalopods and gastropods.
Reference:
1. “Bivalves, Cephalopods, and Gastropods.” Mollusks, Available here.
2. Neupane, Laxmi. “Phylum Mollusca- Characteristics, Classification, Examples.” Microbe Notes, 23 Mar. 2020, Available here.
Image Courtesy:
1. “Squid komodo” By Nhobgood – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Grapevinesnail 01a” By Grapevinesnail_01.jpg: Jürgen Schonerderivative work: Tim Ross (talk) – Grapevinesnail_01.jpg (CC BY-SA 3.0) via Commons Wikimedia