Whales, the ocean’s largest inhabitants, often host a variety of organisms on their bodies. Among these are creatures commonly referred to as “whale lice.” While they might sound similar to human lice, the “lice” found on whales are biologically distinct from their terrestrial namesakes. These specialized marine animals live their entire lives attached to their colossal hosts.
Understanding Whale Lice
What are commonly known as whale lice are not insects, but specialized crustaceans belonging to the family Cyamidae, also called cyamids. They are more closely related to skeleton shrimp than to human lice.
Whale lice possess a distinctly flattened body, which helps them maintain a low profile and cling firmly to the whale’s skin even in turbulent ocean waters. Their legs, particularly the rear three pairs, have developed into strong, claw-like appendages, enabling them to securely attach to their host.
These crustaceans vary in size, typically ranging from 5 to 25 millimeters in length. Many species are unique to a single whale species, highlighting their specialized existence. They are obligate organisms, meaning they live their entire lives on a whale host and do not have a free-swimming stage. If dislodged, they cannot survive for long in the open ocean.
Life on a Whale Host
Whale lice inhabit specific areas on their hosts, often seeking protection from strong water currents. They are frequently found in natural crevices such as around the eyes, blowholes, and genital slits. These crustaceans also congregate in skin lesions, open wounds, or within barnacle colonies that grow on some whales. On certain species, like right whales, they are prominently visible on raised, callus-like patches of skin called callosities.
Once attached, whale lice use their specialized claws to grip onto the whale’s skin. Their mobility is limited, as they are adapted for clinging rather than swimming freely. Their diet primarily consists of dead skin cells and algae that accumulate on the whale’s body. They also feed on fluids from open wounds and damaged tissue.
Impact and Relationship
The relationship between whale lice and their hosts is complex, often considered commensal. The lice benefit without significantly harming the whale, even providing a cleaning service by consuming dead skin and algae. However, in some instances, especially when numbers are large or if the whale is already compromised, they can be mildly parasitic.
Large infestations may cause skin irritation. Secondary infections can also develop in open wounds heavily populated by these crustaceans. Despite these potential impacts, whale lice are generally not life-threatening to healthy whales. Whales sometimes engage in behaviors such as breaching, rubbing against the sea bottom, or rubbing against other whales to dislodge the lice. These actions can offer some relief from the presence of the crustaceans.