The mantis shrimp is a marine crustacean celebrated for its extraordinary biological features, including its hyper-complex visual system and a raptorial appendage that strikes with the acceleration of a rifle bullet. This powerful creature, a member of the Stomatopoda order, demonstrates surprisingly long lifespans compared to many similarly sized invertebrates, which often live for a year or less. This longevity is directly tied to specific physiological traits and behavioral adaptations that allow some species to persist for decades in the ocean environment.
The Lifespan Spectrum: Species Variation and Expected Longevity
The question of how long a mantis shrimp lives does not have a single answer, as longevity varies significantly across the approximately 500 known species. For many smaller, common species, such as the spearer Squillids, the typical lifespan ranges between two and six years in the wild or captivity.
In contrast, larger species, particularly smashers like the peacock mantis shrimp (Odontodactylus scyllarus), exhibit extraordinary longevity. While their average lifespan is often cited in the five-to-seven-year range, certain individuals have been known to live for up to 20 years. This maximum lifespan is remarkably long for a crustacean and rivals that of some decapod species, such as lobsters.
The largest species, such as those in the Lysiosquillina genus, also fall into the category of exceptionally long-lived stomatopods. This distinction suggests that size and growth pattern are closely linked to the overall duration of their lives. Measuring the exact age of a wild mantis shrimp is challenging due to their secretive, burrowing nature.
Biological Drivers of Extreme Longevity
The extended lifespan observed in some mantis shrimp species is driven by specific internal biological mechanisms related to growth and metabolism. These crustaceans exhibit indeterminate growth, meaning they continue to grow slowly throughout their entire lives rather than reaching a fixed maximum size. This steady, slow growth pattern is unlike the determinate growth seen in many short-lived organisms.
This slow, indeterminate growth is correlated with a relatively low metabolic rate compared to fast-growing crustaceans of a similar size. Lower oxygen consumption rates have been observed as the body weight of a mantis shrimp increases, suggesting that larger, older individuals possess a reduced metabolism. A slower metabolic pace is linked to increased longevity because it reduces the accumulation of metabolic waste and cellular damage over time.
The mantis shrimp’s habit of constructing and occupying secure, U-shaped burrows also provides substantial protection from external threats. This sheltered, solitary lifestyle reduces exposure to predation and environmental stress, supporting a long life.
Reproductive Cycles and Parental Investment
The reproductive strategy of the mantis shrimp is closely tied to its requirement for a long lifespan, as it is a species that reproduces multiple times over its life (iteroparity). Unlike many marine invertebrates that release eggs and sperm with no further care, many mantis shrimp species exhibit extensive parental investment.
The female typically remains inside her burrow, guarding, cleaning, and aerating the mass of fertilized eggs for an extended period. This brooding phase can last for one to three months; for example, one species has a mean egg-brooding period of 62 days. During this time, the female often does not leave the burrow to feed, relying on stored energy reserves.
This long-term parental commitment requires the adult to survive long enough to successfully complete the reproductive cycle multiple times. The larvae eventually hatch and enter a planktonic stage for several weeks before settling. The energy and time demanded by this reproductive strategy necessitate a long life history, maximizing the parent’s investment in each reproductive event.