Generally, the whales in the genus Mesoplodon are small. The maximum adult length ranges from 4.3 meters to 6.15 meters. Males of this species can reach a maximum weight of 1500 kg. These whales have relatively small heads, large thoraxes and abdomens, and short tails (as compared to other toothed whales).

Mesoplodon species also have a pair of throat grooves. These are found on the ventral side of the head between the lower jaws. A notch occurs in the center of the flukes. The flipper has a short phalangeal portion. This is typical of the family Ziphiidae. The dorsal fin is small and sub-triangular. It is positioned about two-thirds of the way back on the animal.

Adult male M. carlhubbsi are usually dark gray to black except for two white patches on the head. One patch covers the tip of the rostrum and lower jaw back to the posterior border of the teeth. The other patch occurs in a roughly circular pattern, about 30 centimeters in diameter, centered around the blowhole.

The functional teeth in males are large and straight-sided. They are located near the middle of the mouth. These remain exposed when the mouth is closed.

Adult female M. carlhubbsi are usually medium-gray on the dorsal surface of their bodies. Their sides are a lighter shade of gray. The belly is white. Also, the area of the body just posterior to the flipper, termed the flipper pocket, is darker in color than the surrounding body. The front half of the rostrum and lower jaw are lighter in color than the rest of the head.

The functional teeth of females are smaller than those of the males. They often don’t erupt above the gums.

In both sexes of M. carlhubbsi, the bottom side of the flukes is lighter than the top side. They also have concentric striations that radiate anteriorly from the terminal caudal vertebrae.

Range mass: 1500 (high) kg.

Average mass: 1500 kg.

Range length: 4.3 to 6.15 m.

Sexual Dimorphism: sexes colored or patterned differently; male more colorful