Purpose

The Land Hermit Crab Owners Society (LHCOS) established Hermit Crab Shell Standards to promote ethical care, improve captive welfare, and reduce harm to wild hermit crab populations.

Shells are not decorative accessories. They are essential, life-supporting resources that directly affect a hermit crab’s growth, safety, ability to molt, and long-term survival. Improper shell options are a leading cause of stress, injury, failed molts, and premature death.

This page outlines what constitutes an acceptable shell, what should be avoided, and why shell standards matter for both captive care and conservation.

Why Shell Standards Matter

Hermit crabs do not grow their own shells. They must continuously upgrade as they grow, often maintaining several preferred shells at any given time. When appropriate shells are unavailable, crabs may:

  • Fight or cannibalize tank mates
  • Delay or fail molts
  • Suffer physical injury or shell abandonment
  • Experience chronic stress that shortens lifespan

In the wild, shell scarcity caused by human removal has similar consequences, disrupting entire coastal ecosystems.

Acceptable Shell Standards

Shells provided to hermit crabs should meet all of the following criteria.

Natural and Unaltered

  • Real, natural shells only
  • No paint, glaze, varnish, sealant, or dye
  • No artificial coloring or surface treatments

Why Painted and Coated Shells Are Harmful

Hermit crabs depend on shells not just for protection but as essential components of their biology. Shells provide defense from predators, regulate moisture and body temperature, and allow crabs to safely molt and grow. Alterations to this fundamental resource can have serious negative consequences for crab welfare and survival.

Disruption of Natural Shell Selection

Hermit crabs rely on chemical, tactile, and physical cues to evaluate and select new shells. Scientific research on hermit crab shell use shows that crabs are highly selective and will often assess multiple shells before choosing one, preferring those that best meet their needs for fit, weight, and protection.

Paint or coatings on shells alter:

  • surface texture
  • chemical cues that crabs use to assess suitability
  • weight and balance of the shell

These changes can interfere with natural shell exchange behavior and reduce the likelihood that a hermit crab will choose a painted shell when given safe, natural alternatives. Because shell choice directly affects survival functions like defense, mobility, and molting, interference with this process increases stress and risk.

Chemical and Physical Hazards

Paints, varnishes, and similar coatings often contain compounds that are not tested or certified for use with crustaceans. While regulatory systems in some countries restrict certain toxic substances in consumer products, many paints used on novelty shells originate overseas with minimal oversight.

  • Hermit crabs frequently pick at or modify shells to make them fit better, which can cause them to chip coating materials that may enter the habitat or be ingested.
  • Painted or coated surfaces can trap moisture and disrupt airflow inside the shell, creating conditions that favor bacterial or fungal growth rather than the dry, ventilated environment crabs need for healthy gas exchange.

Because hermit crabs often store water within their shells for breathing and physiological regulation, any alteration that inhibits normal moisture control can lead to stress, increased susceptibility to illness, or mortality.

Physical Harm From Forced Shell Removal

In addition to the risks posed by painted shells themselves, the process by which hermit crabs are placed into painted shells has been documented as physically harmful.

Undercover investigations conducted by PETA documented conditions at facilities supplying the hermit crab pet trade, including Brelean Corporation. Video footage shows hermit crabs being forcibly removed from their natural shells, sometimes by cracking or breaking the shell, leaving the crab exposed and vulnerable.

Documented outcomes included:

  • Crabs with missing limbs or damaged abdomens
  • Crabs left without shells and forced to choose from painted shells
  • High mortality rates following shell removal
  • Crabs exhibiting signs of severe stress and injury

Shell removal is not a natural or benign process. In the wild, hermit crabs voluntarily exchange shells. Forcing a crab from its shell causes unnecessary physical trauma, extreme stress, and significantly increases the risk of death.

Summary of Key Harm Pathways

  • Behavioral disruption: Altered shells interfere with natural assessment and exchange behaviors that are critical to survival.
  • Chemical and moisture risk: Paints and coatings can introduce harmful compounds and trap moisture, increasing the risk of illness and toxic exposure.
  • Physical harm from forced shell removal: Documented industry practices show crabs suffering injury and stress during forced shell replacement processes.

Sources and Citations

Hermit crab shell selection and behavior

Painted shell risks and husbandry impacts

Forced shell removal and industry practices

Proper Species and Shape

Shell preferences vary by species, but commonly accepted shell types include:

  • Turbo species (various sizes)
  • Jade Turbo
  • Petholatus (for larger crabs)
  • Other smooth, round-opening marine shells appropriate to the species

Shells should have:

  • A smooth interior
  • A natural opening shape
  • No sharp edges or drilled holes

Appropriate Sizing and Quantity

  • Multiple sizes must be offered at all times
  • Shell openings should be slightly larger than the current shell opening
  • Crabs should always have several viable options

A single “upgrade shell” is not sufficient. Choice is critical.

Clean and Safe Preparation

Before offering shells:

  • Clean thoroughly
  • Boil to sanitize
  • Allow to cool completely
  • Do not apply oils, sealants, or polish

Shells That Do Not Meet Standards

The following shell types do not meet ethical shell standards and should not be used:

  • Painted or decorative shells
  • Shells with glued embellishments
  • Lacquered or polished shells
  • Cracked or sharp-edged shells
  • Artificial or resin shells
  • Shells drilled or modified for crafts

Painted shells are particularly harmful and are widely associated with injury, stress, and shortened lifespans.

Conservation Considerations

Shell standards apply beyond captivity.

Removing shells from beaches and natural habitats reduces available housing for wild hermit crabs and other shell-dependent species. Empty shells are not souvenirs — they are critical habitat.

Responsible conservation behavior includes:

  • Leaving shells in natural environments
  • Supporting shell restoration and education efforts
  • Avoiding the purchase of shells sourced irresponsibly

Ethical Sourcing Guidance

When acquiring shells:

  • Choose sellers who prioritize ethical sourcing
  • Avoid bulk craft shells or tourist souvenirs
  • Seek education-focused suppliers aligned with animal welfare

LHCOS encourages caretakers to source shells responsibly and to prioritize animal safety over aesthetics.

Relationship to LHCOS Programs

These shell standards support and inform:

  • LHCOS educational materials
  • Approved Sellers criteria
  • Adoption and rehoming guidance
  • Classroom and outreach programs

They are intended to provide clarity and consistency across the community.

Related Resources

Summary

Ethical shell choices save lives.
Providing natural, safe, appropriately sized shells reduces stress, prevents injury, supports successful molting, and helps protect wild populations.

Shells are not optional — they are essential.

Educational Disclaimer

These standards establish minimum ethical care expectations. They do not replace veterinary or professional consultation where available. Individual needs may vary by species and environment.