Are Shrimp and Roaches in the Same Family?

Shrimp and roaches share some similarities in appearance and behavior, leading to the common question – are shrimp and roaches in the same family? While they have some superficial resemblances, shrimp and roaches belong to completely different biological families

Roaches are insects in the Blattodea order, while shrimp are crustaceans in the suborder Dendrobranchiata They are distant relatives as arthropods, but have evolved very differently over millions of years

In this article, we’ll explore the reasons for the “sea roach” nickname for shrimp, while clarifying the major differences that separate them into distinct families. Read on to learn why comparing shrimp to roaches is inaccurate from a biological perspective.

Why Are Shrimp Called “Sea Roaches”?

There are several reasons why shrimps earned the unflattering moniker of “sea roaches” or “cockroaches of the sea”:

• Segmented bodies and hard exoskeletons
• Long antennae for sensing their environment
• Numerous legs for mobility and swimming
• Scavenging food sources
• Ability to thrive in less-than-ideal conditions
• Resilience and adaptability

These shared physical traits and survival behaviors cause shrimps and roaches to resemble each other in some ways. However, taxonomy based on genetics and evolution reveals they are unrelated.

Comparing Shrimp and Roach Biology

While they occupy similar ecological niches, shrimps and roaches have key biological differences that place them in distinct classifications:

Habitats

• Shrimp are exclusively aquatic, living in oceans, seas, lakes and rivers.
• Roaches are land-dwelling and cannot survive underwater.

Respiration

• Shrimp breathe through gills to extract oxygen from water.
• Roaches have spiracles and tracheae for air breathing.

Number of Legs

• Shrimps have 8-10 legs for swimming.
• Roaches have 6 legs for walking and running.

Body Segments

• Shrimps have a 2-segmented body of cephalothorax and abdomen.
• Roaches have a 3-part body of head, thorax and abdomen.

Reproduction

• Most shrimp spawn by releasing eggs into water.
• Roaches develop in egg cases carried by the female.

Order and Suborders

• Shrimp belong to Decapoda order and Dendrobranchiata suborder.
• Roaches belong to Blattodea order, with 4 suborders of cockroaches.

Diet

• Shrimp are omnivores that filter feed or scavenge.
• Roaches are omnivores and opportunistic feeders.

So while they occupy similar feeding niches, shrimp and roaches arrived there through separate evolutionary paths – they are not closely related when taxonomy is considered.

Are Shrimp and Roaches Classified in the Same Family?

Shrimp and roaches are not even remotely related when families are considered. Here’s how the classification compares:

Shrimp Taxonomy

Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Class: Malacostraca
Order: Decapoda
Suborder: Dendrobranchiata

Roach Taxonomy

Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Blattodea

They are as genetically distinct from one another as lions and house cats, despite certain superficial similarities.

Reasons for “Cockroaches of the Sea” Nickname

Shrimp comport themselves in ways that resemble land-based roaches, leading to the unflattering moniker:

• Scavenging along ocean floors and habitats
• Foraging for food opportunistically
• Ability to consume decaying organic matter
• Thriving in adverse conditions
• Producing large numbers of offspring

So while not biologically related, shrimp and roaches occupy similar niches in their respective habitats. But they clearly belong to completely different family lineages.

Persistence of the “Sea Roach” Myth

Despite scientific evidence that shrimp and roaches are unrelated, the “sea roach” myth persists. Reasons this inaccurate comparison continues include:

• Visible similarities in body segmentation and antennae
• Lack of public knowledge of taxonomy and evolution
• Nickname evokes a strong reaction due to roach perceptions
• Simple explanation that shrimp “look like roaches”

While useful for eliciting reactions, comparing shrimp to roaches remains biologically incorrect. Educating the public on how taxonomy and genetics differentiate the two can help dispel this inaccurate myth.

Benefits of Classifying Shrimp Accurately

Calling shrimp “sea roaches” may seem harmless, but it has subtle negative effects:

• Perpetuates myth instead of facts
• Contributes to seafood misinformation
• Generates misplaced disgust or avoidance of shrimp
• Dissuades people from eating highly nutritious shrimp
• Leads to miscategorizing threats to shrimp populations

Viewing shrimp as genetically unique organisms, rather than crudely as “bugs of the sea”, can positively impact human behaviors and environmental policies.

The Takeaway

While they share some attributes that explain the nickname, shrimp and roaches are completely distinct organisms scientifically. Beyond visible commonalities, genetics and evolution separate them definitively into different biological families. Being accurate when classifying shrimp helps uphold scientific integrity.

So next time someone refers to shrimp as “sea roaches”, politely explain the biological facts. Fighting this myth through education helps ensure shrimp are perceived correctly, not just as misunderstood bugs.