The goblin shark, scientifically known as Mitsukurina owstoni, is a rarely seen deep-sea inhabitant. This species is often referred to as a “living fossil” because it is the sole surviving member of an ancient lineage dating back 125 million years. Its distinctive appearance, featuring a long, flat, blade-like snout and a pinkish body, makes it instantly recognizable, yet its deep-dwelling nature ensures it remains largely a mystery to science. The difficulty in observing and capturing this creature is the primary reason why precise measurements, particularly its weight, are so variable and challenging to obtain.
Estimated Weight of Mature Specimens
The weight of a mature goblin shark is typically estimated to be in the range of 150 to 210 kilograms (330 to 463 pounds). This range represents the size of most adult specimens accidentally caught as bycatch in deep-sea fisheries around the world. For instance, the heaviest specimen officially recorded was a shark measuring 3.8 meters (12.5 feet) in length, which weighed 210 kg (460 pounds).
The body composition of the goblin shark is adapted for life in the deep ocean, which influences its weight relative to its size. A significant portion of its mass comes from its liver, which can account for up to 25% of its total body weight. This large, oily liver helps the shark maintain neutral buoyancy in the water column, conserving energy in an environment with limited food resources.
Female goblin sharks are thought to grow larger than males. While the typical adult weight is around 200 kg, a recent, heavily pregnant female specimen was recorded at 4.7 meters (15 feet) and weighed an astonishing 800 kg (1,800 pounds). This exceptional measurement suggests that the upper limit of the species’ weight is far greater than previously understood, particularly for gravid females.
Length and Maximum Recorded Size
The weight figures for the goblin shark are closely tied to its length, as scientists often use allometric scaling to estimate mass from a known length measurement. Typical adult goblin sharks reach lengths between 3 and 4 meters (9.8 and 13.1 feet). Males reach sexual maturity at a length of about 2.6 meters (8.5 feet), suggesting that any specimen below this size is still considered a juvenile or sub-adult.
The maximum size for the species is a subject of debate due to the rarity of large captures. However, there have been estimates of significantly larger individuals that provide context for the species’ potential upper size limits.
One notable estimate concerns an enormous female captured in 2000, which was believed to have a total length between 5.4 and 6.2 meters (18 and 20 feet). While the actual weight of this specimen was not recorded, a shark of this length would dwarf the typical adult size and represent the absolute maximum size of the species. These estimated lengths suggest that the largest goblin sharks are substantially heavier than the typical 200 kg adults, likely corresponding to the 800 kg weight of the pregnant female or even more.
Deep-Sea Habitat and Measurement Difficulty
The scarcity and variability of precise weight data are directly attributable to the goblin shark’s preferred habitat. This species is benthopelagic, meaning it lives near the ocean floor, typically along the outer continental slopes and seamounts. Most individuals are found at depths ranging from 270 to 960 meters (890 to 3,150 feet), although they have been documented as deep as 1,300 meters.
The extreme pressure and low temperatures of this environment make direct observation and capture exceedingly difficult. Almost all specimens studied by researchers have been caught unintentionally as bycatch in deep-sea trawling or longline fishing operations. The logistical challenge of bringing these fragile, deep-water animals to the surface often results in damage to the specimen, which compromises the accuracy of post-mortem measurements.
The goblin shark’s soft, flabby body structure and poor musculature, which are adaptations for life in a low-energy environment, also contribute to measurement imprecision. Once removed from their high-pressure environment, their bodies can be easily distorted, making exact length and weight measurements difficult to obtain.