Crawdads, also known as crawfish or crayfish, are fascinating freshwater crustaceans. While primarily aquatic, spending most of their lives submerged, they possess a remarkable ability to survive outside water for varying periods. Understanding how long crawdads can endure out of water, and the conditions that influence their survival, is important for anyone encountering them. This article explores the factors governing their out-of-water endurance.
Factors Influencing Out-of-Water Survival
A crawdad’s ability to survive outside of water is not uniform; it depends on several environmental and biological factors. Crawdads breathe using feather-like gills, which extract dissolved oxygen from water. Out of water, these gills can still pull oxygen from the air, but they must remain consistently moist for gas exchange. If their gills dry out, the crawdad will suffocate.
Humidity plays a key role in maintaining gill moisture. In very high humidity, some crawdad species can survive for several days, or even months, outside of water. At 100% humidity, crawdads can survive over 30 days, while lower humidity levels (30-70%) reduce their survival time to 2 to 7 days. Temperature also impacts survival, as extreme heat or cold can deplete a crawdad’s energy and cause stress. While crawdads generally prefer water temperatures between 22-26°C (71.6-78.8°F), prolonged exposure to temperatures outside this range is detrimental.
The species of crawdad influences its desiccation resistance. Some burrowing species tolerate dry conditions better, surviving months within humid burrows they construct. For instance, the Red Swamp Crayfish and Signal Crayfish are known for their ability to withstand dryness, with the red swamp crayfish surviving up to four months of drying out.
Conversely, smaller species, such as some dwarf crayfish, may only survive 48 hours without water. Overall health and physical condition also contribute to resilience, with healthier specimens having a better chance of enduring time out of water.
Supporting Crawdad Survival Outside Water
When crawdads are temporarily out of their aquatic environment, providing appropriate conditions can extend their survival. Keep their gills and entire body damp. This can be achieved by periodically misting them with dechlorinated, room-temperature water or by placing them on a moist substrate, such as a damp cloth or newspaper. It is important to use dechlorinated water, as chlorine in tap water can be harmful to aquatic life.
Temperature control is also important. Keeping crawdads cool, but not frozen, reduces their metabolic rate and conserves energy. A common method for short-term storage involves placing ice on top of a sack containing crawdads, allowing the slow meltwater to keep them cool and moist, while ensuring adequate air circulation. Avoid placing them in direct sunlight.
Minimizing stress during handling and transport is beneficial, as improper housing or excessive movement can weaken them. Crawdads should never be fully submerged in standing water in a closed container, or left to sit in melted ice water, as they require access to atmospheric oxygen and can drown without proper air circulation.
Recognizing and Responding to Distress
Identifying signs of distress in a crawdad is important for timely intervention. Poor health or environmental stress can cause noticeable changes in behavior and appearance. Common indicators include lethargy or a decrease in activity, with the crawdad appearing sluggish or unresponsive. Erratic movements or an increased tendency to hide more than usual also signal distress. Changes in coloration, such as fading hues, discoloration, or unusual spots, are visual cues of problems.
A distressed crawdad might also show a decreased appetite or refuse food. Issues with molting, where the crawdad struggles to shed its exoskeleton, are a sign of ill health. In some cases, a crawdad might attempt to escape its current environment if it perceives conditions as unfavorable.
If a crawdad has been out of water for an extended period, a curled tail can indicate severe dehydration and distress. When reintroducing a distressed crawdad to water, it should be done slowly and gently, preferably into conditioned water at room temperature to prevent further shock. After reintroduction, observe them, ensuring optimal water quality and providing hiding spots to help them recover and acclimate.