Pacific Rim Divers Limited

Blue Dragon Nudibranch

Common name: Blue Dragon Nudibranch
Scientific name: Pteraeolidia semperi
Hawaiian name: No documented name

Series of photos of a Blue Dragon Nudibranch at the Octocoral dive site in Kona. This aeolid nudibranch hosts symbiotic zooxanthellae in its tissues, which provide energy through photosynthesis. Individuals feed on hydroids and retain the algae from their prey. The long cerata increase surface area for both defense and light exposure. This species is widespread across the Indo Pacific and is occasionally found in Hawaiʻi.

🧠 Fun fact: Because of the zooxanthellae living inside its body, Pteraeolidia semperi can survive for extended periods without feeding as long as it receives enough light.

.cameras E-M10 Mark 4 in a AOI housing w/Hybrid Flash, M.Zuiko 90mm and Sola spotting light. computers!

.life.explorer

Commensal Shrimp on Pincushion Star

Common name: Commensal Shrimp
Scientific name: Zenopontonia soror
Hawaiian name: No documented name

Photo of a commensal shrimp on a pincushion starfish (Culcita novaeguineae) at the Driftwood dive site in Kona. Z. soror lives on cushion stars and gains protection and camouflage from the host. The shrimp matches the color and texture of the starfish surface and feeds on small particles and mucus on the host’s skin. The relationship is considered commensal because the shrimp benefits while the starfish is not harmed.

🧠 Fun fact: Zenopontonia soror often stays with the same cushion star for long periods, showing strong host fidelity.

.cameras E-M10 Mark 4 in a AOI housing w/Hybrid Flash, M.Zuiko 90mm and Sola spotting light. computers!

.life.explorer

Whitemouth Moray - Gymnothorax meleagris (possible)

Common name: Whitemouth Moray
Scientific name: Gymnothorax meleagris
Hawaiian name: phi ‘ōni’o

Series of photos of a very small moray at the Driftwood dive site in Kona. The spotted pattern and pale mouth lining are consistent with a juvenile Whitemouth Moray, though size and coloration can vary among young morays, so the identification is tentative. Whitemouth morays shelter in crevices during the day and hunt fishes and crustaceans at night. Juveniles often show more distinct spotting than adults.

🧠 Fun fact: Juvenile morays can look dramatically different from adults, and several Hawaiian species overlap in patterning, which makes small individuals some of the hardest eels to identify.

.cameras E-M10 Mark 4 in a AOI housing w/Hybrid Flash, M.Zuiko 90mm and Sola spotting light. computers!

.life.explorer

Trembling Nudibranch — Goniobranchus vibratus

Common name: Trembling Nudibranch
Scientific name: Goniobranchus vibratus
Hawaiian name: No documented name

Series of photos of a Trembling Nudibranch at the Driftwood dive site in Kona. This chromodorid nudibranch is known for the rapid, wave‑like movements of its mantle edge, a behavior used for signaling and possibly deterrence. Individuals feed on specific sponge species and store defensive chemicals from their prey. They occur on shallow to moderate reef habitats across Hawaiʻi and the Indo‑Pacific.

🧠 Fun fact: The vibrating mantle motion that gives this species its name is produced by rhythmic contractions along the mantle margin — a behavior not common among other chromodorids.

.cameras E-M10 Mark 4 in a AOI housing w/Hybrid Flash, M.Zuiko 90mm and Sola spotting light. computers!

.life.explorer

Commerson’s Frogfish — Antennarius commerson

Common name: Commerson’s Frogfish / Giant Frogfish
Scientific name: Antennarius commerson
Hawaiian name: No documented name

Photo of a Commerson’s Frogfish at the Driftwood dive site in Kona. This species is an ambush predator that uses a modified dorsal spine as a lure to attract prey. Individuals rely on camouflage and remain motionless until small fishes or crustaceans approach, then strike with a rapid mouth expansion that pulls prey inside. A. commerson is widespread across the Indo‑Pacific and is one of the largest frogfish species.

🧠 Fun fact: Commerson’s frogfish can swallow prey nearly their own size thanks to an expandable stomach and a strike speed measured in milliseconds.

.cameras E-M10 Mark 4 in a AOI housing w/Hybrid Flash, M.Zuiko 90mm and Sola spotting light. computers!

.life.explorer

Ceratosoma sp. 2 — Ceratosoma Nudibranch

Common name: Ceratosoma Nudibranch
Scientific name: Ceratosoma sp. 2
Hawaiian name: No documented name

Photo of a Ceratosoma sp. 2 nudibranch at the Driftwood dive site in Kona. This undescribed Ceratosoma species is part of a group known for their mantle lobes and chemical defenses derived from sponge prey. Individuals feed on specific sponge species and are typically found on rocky reef surfaces where their prey occurs.

🧠 Fun fact: Many Ceratosoma species have an enlarged dorsal lobe that acts as a decoy — predators strike the lobe instead of the head, giving the nudibranch a chance to escape.

.cameras E-M10 Mark 4 in a AOI housing w/Hybrid Flash, M.Zuiko 90mm and Sola spotting light. computers!

.life.explorer

Seven‑Eleven Crab — Carpilius maculatus

Common name: Seven‑Eleven Crab
Scientific name: Carpilius maculatus
Hawaiian name: ʻAʻama kuahiwi

Photo of a Seven‑Eleven Crab at the Driftwood dive site in Kona. This species is named for the pattern of dark spots on its carapace, often compared to the layout of dice. It is a nocturnal predator that feeds on mollusks, using strong claws to break shells. Individuals are typically found on rocky reef habitats throughout the Indo‑Pacific, including Hawaiʻi.

A second photo shows a mating pair — sometimes jokingly called the “14/22 crab” when both individuals’ spot patterns are visible. Seven‑Eleven Crabs reproduce through external fertilization: the male transfers a s***matophore to the female, who later releases fertilized eggs that develop into planktonic larvae before settling onto the reef.

🧠 Fun fact: The Seven‑Eleven Crab has some of the strongest claws relative to body size among Hawaiian crabs, allowing it to crack open thick‑shelled prey.

.cameras E-M10 Mark 4 in a AOI housing w/Hybrid Flash, M.Zuiko 90mm and Sola spotting light. computers!

.life.explorer

Stout Moray — Gymnothorax eurostus

Common name: Stout Moray
Scientific name: Gymnothorax eurostus
Hawaiian name: Puhi

Photo of a light‑colored Stout Moray at the Octocoral dive site in Kona. This Indo‑Pacific species has a thick body, rounded snout, and variable coloration that ranges from pale to dark depending on habitat and age. Individuals shelter in crevices during the day and hunt fishes and crustaceans at night. They often occupy the same den for long periods.

🧠 Fun fact: Stout morays can produce low grunting sounds by vibrating throat muscles — one of the few moray species known to vocalize.

.cameras E-M10 Mark 4 in a AOI housing w/Hybrid Flash, M.Zuiko 90mm and Sola spotting light. computers!

.life.explorer

Noumeaella rehderi — Rehder’s Nudibranch

Common name: Rehder’s Nudibranch
Scientific name: Noumeaella rehderi
Hawaiian name: No documented name

Photos of Noumeaella rehderi at the Octocoral dive site in Kona. This small aeolid nudibranch is associated with soft corals and hydroids, where it feeds on cnidarian tissue and incorporates stinging cells for defense. Individuals are typically found on or near their prey colonies.

A second photo shows a mating pair. Nudibranchs are simultaneous hermaphrodites, meaning each individual has both male and female reproductive organs. When two adults mate, they align their bodies side‑by‑side and exchange s***m, allowing both to later lay egg ribbons.

🧠 Fun fact: Many aeolid nudibranchs, including N. rehderi, store the stinging cells from their prey in specialized sacs called cnidosacs — a defensive strategy unique to this group.

.cameras E-M10 Mark 4 in a AOI housing w/Hybrid Flash, M.Zuiko 90mm and Sola spotting light. computers!

.life.explorer

Giant Moray: Gymnothorax javanicus

Common name: Giant Moray
Scientific name: Gymnothorax javanicus
Hawaiian name: Puhi

Photo of the head of a Giant Moray at the Driftwood dive site in Kona. The full animal was nearly 8 feet long, making it one of the largest moray species found in the Indo‑Pacific. This species shelters in crevices during the day and hunts fishes and crustaceans at night. Individuals have a broad head, strong jaws, and mottled coloration that varies with age and habitat.

🧠 Fun fact: Giant morays often maintain long‑term home ranges and may use the same den for years, which makes sightings of large adults uncommon, this was the first time I’ve been able to photograph one.

.cameras E-M10 Mark 4 in a AOI housing w/Hybrid Flash, M.Zuiko 90mm and Sola spotting light. computers!

.life.explorer