COLDWATERS C I E N C EA journal of marine life
& ocean exploration
COLDWATER SCIENCE / ANIMAL FIELD GUIDES
Explore shells, arms, life cycles, molting and photosynthetic partnerships in octopuses, nautiluses, crustaceans, jellies, clams and coral animals.
60 animal articles · Scientific references · Credited cover images
7 articles
Colored pencil and gouacheInvertebrates
The giant Pacific octopus combines color-changing skin, texture changes and sensory suckers to navigate and blend into its surroundings. Females guard egg strings while fasting; hatchlings enter a planktonic stage, and the species’ typical lifespan estimate is three to five years.
Read the animal guide →
Wildlife photographInvertebrates
A nautilus’s shell compartments help regulate buoyancy, while a separate jet propels it. Its anatomy, lensless eyes and slow reproductive pace distinguish it from familiar cephalopods and help explain its vulnerability to collection.
Read the animal guide →
Wildlife photographInvertebrates
Blue crabs grow by shedding a rigid exoskeleton, and their life cycle shifts among estuarine habitats. Paddling legs, sex-specific abdominal shapes, larval stages and a North Carolina tagging study help explain how to read their biology and movement evidence.
Read the animal guide →
Wildlife photographInvertebrates
American lobsters grow by molting, use their differently shaped claws for different tasks, and carry eggs beneath the tail. Their age is difficult to establish, so size and possible longevity estimates should not be mistaken for a known birthday or lifespan.
Read the animal guide →
Cyanotype-style artworkInvertebrates
A moon jelly’s familiar bell is only its swimming adult stage. Across the genus Aurelia, sexual reproduction, settling larvae, attached polyps, budding and strobilation connect that visible medusa to less visible stages that can produce many young jellies.
Read the animal guide →
Wildlife photographInvertebrates
Giant clams combine suspension feeding with nutritional support from photosynthetic dinoflagellates living in mantle tubules. Their size, shell form and reef habitat vary by species; the largest, Tridacna gigas, faces documented harvest pressure across much of its range.
Read the animal guide →
Wildlife photographInvertebrates
Corals are animals built from solitary or colonial polyps, and some stony corals add calcium carbonate skeleton that forms reef framework. Shallow reef corals may host photosynthetic algae, while deep-water corals feed without sunlight-dependent partners.
Read the animal guide →