The key difference between sea hare and nudibranch is that sea hare is a herbivorous mollusc that belongs to order Anaspidea, while nudibranch is a carnivorous mollusc that belongs to order Nudibranchia.
Phylum Mollusca consists of soft-bodied organisms. Sea slugs are marine gastropods that belong to phylum Mollusca. Sea hare and nudibranch are two types of sea slugs which are often mistaken to each other. They belong to two different orders. Sea hare belongs to order Anaspidea while nudibranch belongs to order Nudibranchia. Moreover, sea hare is herbivorous while nudibranch is carnivorous.
CONTENTS
1. Overview and Key Difference
2. What is Sea Hare
3. What is Nudibranch
4. Similarities Between Sea Hare and Nudibranch
5. Side by Side Comparison – Sea Hare vs Nudibranch in Tabular Form
6. Summary
What is Sea Hare?
‘Sea hare’ is a common name that refers to herbivorous gastropod molluscs belonging to the large group or order Anaspidea. Most sea hares belong to the genus Aplysia. The name is given to them due to the presence of head tentacles or rhinophores that resemble a hare’s ears.
Figure 01: Sea Hare
Sea hares are herbivorous and eat seaweeds. The body of many sea hares has two flaps, and their gills are enclosed in the body mantle. They do not possess a hard shell, but some sea hares possess internal shells.
What is Nudibranch?
Nudibranch is commonly known as sea slugs. Nudibranchs are marine gastropod molluscs belonging to order Nudibranchia. There are more than 3000 nudibranchs species, and they are brightly coloured sea slugs. They have a pair of stalked rhinophores or horns at the head. They use these head tentacles to sense their surroundings and chemical signals. Moreover, they have oral tentacles that are visible. Generally, nudibranchs do not have external shells. Some members of nudibranchs have flowery gills while some don’t have external gills.
Figure 02: Nudibranch
The name ‘nudibranch’ has been given to them due to the feathery and brightly-coloured naked gills they have. Their bodies are made up of two flaps. Unlike sea hares, nudibranchs are carnivorous; they eat animals such as sponges, bryozoans and polyps.
What are the Similarities Between Sea Hare and Nudibranch?
- Both sea hare and nudibranch do not have hard shells.
- They are gastropod molluscs.
- Both types are soft-bodied invertebrates.
- Moreover, they are marine organisms.
- They have rhinophores.
- Some nudibranch and many sea hares have a body made up of two flaps.
- Sea hare and nudibranch are bilaterally symmetrical.
- Furthermore, they are hermaphroditic.
What is the Difference Between Sea Hare and Nudibranch?
Sea hares are a type of gastropod molluscs that have soft bodies with an internal shell. Meanwhile, nudibranchs are a type of gastropod molluscs that have no external shells but have naked gills. So, this is the key difference between sea hare and nudibranch.
Moreover, these two types of gastropods belong to two different orders; sea hare belongs to order Anaspidea, while nudibranch belongs to order Nudibranchia. Another significant difference between sea hare and nudibranch is that sea hare is herbivorous, while nudibranch is carnivorous.
Below infographic summarizes the differences between sea hare and nudibranch.
Summary – Sea Hare vs Nudibranch
Sea hare and nudibranch are two types of marine gastropod molluscs. Sea hare has an internal shell and belongs to the order Anaspidea. In contrast, nudibranch is a shell-less marine gastropod which has naked gills. They belong to order Nudibranchia. Moreover, nudibranchs are brightly coloured and they use these bright colours to warn predators. Furthermore, sea hares are herbivorous while nudibranchs are carnivorous. So, this is the summary of the difference between sea hare and nudibranch.
Reference:
1. “Anaspidea.” Wikipedia, Wikimedia Foundation, 31 Dec. 2019, Available here.
2. Hakai Magazine. “Nudibranchs: Armed and Fabulous.” Hakai Magazine, Available here.
Image Courtesy:
1. “Aplysia fasciata, mottled sea hare (Sea slug), γυμνοσάλιαγκας θαλάσσης By Dimitris Siskopoulos (CC BY-SA 2.0) via Flickr
2. “Berghia coerulescens (Laurillard, 1830)” By Parent Géry – Own work, cropped (Public Domain) via Commons Wikimedia
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