BEHAVIOR

Extended clips of interesting behaviors with commentary*

*by this non-biologist so please let me

know if it’s not scientifically accurate

Burrowing Brittle Stars Transport Food Along Arms

California, Indonesia and the Philippines — 2013-2017

Burrowing brittle stars bury themselves in sand or rubble bottoms with two or three legs sticking up. They use the protruding legs to filter feed, then sequentially flex their tube feet to transfer the food particles down along the arms and into their mouths.

added 11/7/2020

Amphipod Attacks Pteraeolidia Eating Its Hydroid Home

Tulamben, Bali, Indonesia — July 2015

Colorful flea-sized amphipods can often be found living on flower-like hydroids on the sandy slopes of the Indo-Pacific. Unfortunately for the amphipods, these hydroids are a favorite food of several nudibranchs. Here, one plucky little amphipod tries in vain to defend his hydroid home.

added 10/17/2020

Lined Sea Hare Mating Aggregation

Triton Bay and Tulamben, Bali, Indonesia — 2015-2019

Stylocheilus striatus, also known as a lined sea hare, is a sea slug that can be found in tropical oceans around the world. They sometimes form mating chains or large aggregations to increase fertilization efficiency. In one case here, an emperor shrimp joins the party.

added 9/23/2020

Peanut Worm Feeds

Tulamben, Bali, Indonesia — February 2014

Peanut worms, also called sipunculans, are a phylum of worms rarely spotted by divers. Most live in shallow water buried under sand, mud, stones or in rocky crevices. To feed, they extend their anterior section, called the introvert, to collect food particles then draw them into the mouth as the introvert is retracted.

added 7/26/2020

Sea Apples Feed

Komodo and Alor, Indonesia — 2014-2020

Sea apples are a brightly colored type of sea cucumber that live primarily in the cooler-water areas of the Indo-Pacific. Watching them feed is equal parts mesmerizing and disturbing.

added 7/26/2020

Sheep Crab Mounts Camera

Anacapa and Santa Cruz Islands, CA — June-July 2012 and April 2013

Sheep crabs are a type of spider crab, and are the largest species of crab found on the California coast. We see them frequently on our reefs and sometimes we get to witness some interesting (attempted) mating behavior.

added 7/14/2020

Brittle Stars Discs Undulate

Oil Rig Ellen and San Miguel Island, CA — March 2019 and September 2016

California is home to some brilliantly colored brittle stars. If you look closely at their central disk, you can see the top surface undulate.

added 7/3/2020

Dendronotus Iris Pounces on Tube Anemone

San Miguel Island, CA — April 2015 and September 2016

Dendronotus iris, also known as a rainbow nudibranch, is a large sea slug found along the west coast of North America. They feed on tube anemones by sneaking up next to them and pouncing right into the middle, often getting pulled part way into the tube in the process.

added 7/3/2020

Finespotted Jawfish with Eggs

Northern Sea of Cortez, Mexico — August 2013, July 2016 and August 2019

Finespotted jawfish are a large species of jawfish and like most members of the family, they are mouthbrooders. While carrying the eggs in their mouths, they will periodically spit them partially out to churn and aerate them.

added 6/12/2020

Gulf Signal Blenny Displays

Northern Sea of Cortez, Mexico — August 2013, August 2014 and August 2019

Male gulf signal blennies have large sail-like dorsal fins, and they use them to put on a showy display to attract the girls.

added 6/12/2020

Orangethroat Pikeblenny Displays

Northern Sea of Cortez, Mexico — August 2013, August 2014 and August 2019

Male orangethroat pikeblennies put on a flashy display including flamboyant colors and a funky little dance to attract females.

added 6/12/2020

Orangethroat Pikeblennies Hunt and Feed

Northern Sea of Cortez, Mexico — August 2014 and July 2016

Orangethroat pikeblennies hunt with a quick strike and feed on small crustaceans and plankton they find on or near the bottom.

added 6/12/2020

Clown Anemonefish with Tongue Biters

Lembeh Strait, North Sulawesi, Indonesia — September 2013

Parasitic tongue-biter isopods are small crustaceans that attach to and eventually replace a fish’s tongue. Anemonefish are common hosts for these isopods, and we often see affected fish sucking on the anemone tentacles. We’re not sure why, perhaps it’s an attempt to kill the isopod or to numb their mouths to provide pain relief.

added 6/12/2020

Pacific Red Octopus with Eggs

Santa Monica Bay, CA — September 2012

The Pacific red octopus is a small octopus species that lives under rocks in the intertidal and in kelp beds or over rocky or sandy seafloors. Females lay clusters of eggs from late spring to early winter and care for the eggs for six to eight weeks. They die soon after the eggs hatch.

added 6/12/2020

Lizardfish with Triggerfish in Mouth

Sangeang, West Nusa Tenggara, Indonesia — August 2012

Lizardfish are ambush predators that eat other fish. When they catch one, it often takes quite a while for them to swallow it completely, often leaving the victim gasping for breath as it slowly disappears deeper into the lizardfish’s toothy mouth.

added 6/12/2020

Day Octopus Pair Mating

Milne Bay, Papua New Guinea — May 2012

I came across this mating pair of day octopus on a dive and watched them for quite a while as they moved around the reef. They had a hard time finding a place where they wouldn’t be disturbed, if not by annoying videographers, then by marauding fish.

added 6/12/2020

Mating Wunderpus

Anilao, Batangas, Philippines — January 2012

We were lucky to witness this brief mating encounter between two Wunderpus octopuses at the very end of a long dive in Anilao.

added 6/12/2020

Simnia Snail Feeds on Red Gorgonian

Anacapa Island, CA — July 2013

Simnia arcuata is a pretty little snail local to our California waters. They are usually found on red gorgonians, on which they can often be seen grazing as they crawl along.

added 5/31/2020

Sarcastic Fringehead Defends Territory

Anacapa Island, CA — May 2013

These fantastically named fish often take up residence in abandoned shells or bottles. They are afraid of nothing and will aggressively defend their territories against other fish, divers or even their own reflection.

added 5/31/2020

Abalone Feeds on Kelp

Catalina Island, CA — February 2013

Abalone are surprisingly active feeders. When a piece of kelp drifts into range, they stretch up off the rock and grab it.

added 5/31/2020

© 2020 Nannette and Bill Van Antwerp