Nudibranch Preying on a Goby

Nudibranch on Goby Fiji Ned DeLoach Blennywatcher.com

The first time we saw this was in Fiji

Here’s another strange one: A nudibranch that attaches to and eats the fins of shrimp gobies! Shrimp gobies are cool fishes – teaming up with nearsighted burrow-building shrimp, the vigilant gobies act as sentinels, watching for danger, while the shrimp build communal burrows. Life is good out on the sand flat, right? Well yes, until the little nudibranch, Gymnodoris nigricolor, enters the scene.  In the photo, the nudibranch is the little black job hanging onto the fin of the goby.

We were diving in Lembeh back in 2000 when Mary Jane Adams told us about this relationship of the nudibranch on the goby and asked if we had ever seen it in Lembeh. She had recently seen it in the Solomon Islands, which was a range extension, since at that time, it had only been reported from Okinawa. We didn’t even know such a relationship existed, but our guide said he had seen it once at a site called Critter Hunt, so off we all went in search of it.

No luck in Lembeh but in 2005, I found it in Fiji (which I think was the first time it had been recorded there) – but of course at the end of a dive and 65′ deep. Ned got a shot but the goby spooked and darted into its hole, taking the nudibranch with it. We weren’t sure if the nudi would still be hanging on when the goby re-emerged but our allowed dive time was over so we couldn’t stay around to find out. I marked the spot with a very distinctive rock and we planned a second dive so a couple of others could photograph it. A comedy of errors ensued – mainly because I didn’t realize there were two large bommies at the site and the tender driver had dropped us on the other one.  After a little head scratching, I finally saw the second bommie, found my marker rock and the goby with the attached nudibranch! I got a few seconds of video then Burt Jones showed up and got a couple of shots before the goby freaked again and dived into its hole – we marveled at the  strength of the grip the nudibranch had on the goby fin.

Nudibranch on Goby Solomon Islands Ned DeLoach

Nudibranch preying on shrimp goby (Solomon Islands)

Nudibranch on goby Close-up Solomons Ned DeLoach

Close-up nudibranch preying on shrimp goby

In 2009, on a sandy slope in the Florida Islands in the Solomons, I saw another! I was scouting for Ned and by the time he got some photos, the goby decided I was a threat and dived into its hole. The nudibranch hung on during what was a very fast and certainly violent by nudibranch standards, dive by the goby into the burrow.

Bob Bolland’s Okinawa Slug Site has more photos and lists references, including the paper, The First Association of an Adult Mollusk (Nudibranchia: Doridae) and a Fish (Perciformes: Gobiidae) and the 2000,  paper  that confirms the nudibranch does feed on the goby fins – I think before that, the nature of the relationship was speculation. And the paper has a close-up of the hooked radula of the nudibranch’s mouth, which helps explain why the nudi is able to hang on the way it does. I’ve loaded a little bit of video on our BlennyWatcher YouTube channel  so you can see how the nudi hangs on when the goby bolts, or you can click below to watch.

Photo Friday: Twilight

Spawning hamlets Ned DeLoach BlennyWatcher.com

Butter Hamlets spawning

This is our entry for this week’s Photo Friday Challenge: Twilight. Spawning hamlets can be seen at twilight. This is an interesting time on the reef – daytime fishes have bedded down and the night-time feeders haven’t yet emerged from their hiding places. A few fishes, like the normally solitary hamlets, take advantage of the low light (presumably to avoid predators) and pair up at twilight to spawn. Ned calls it the best peep show on the reef.

Yawning Fishes

Yawning Lacy Rhinopias by Ned DeLoach Blennywatcher.com

Excuse me fish, am I boring you? Lacy Rhinopias giving us the full stretch.

We see fish yawn fairly often, but have to be in the right place at the right time to capture the behavior. In Papua New Guinea, this Lacy Rhinopias, a member of the scorpionfish family, was on the same coral head every day for a week so everyone had a chance to photograph it from every angle. Ned saw it yawn from a distance and knew he wanted that head-on shot, so he went back and sat for quite a while, waiting for the right moment to press the shutter button. This is how it usually happens – we see it from a distance then try to position ourselves for the shot and wait. Sometimes the fish will yawn again right away; sometimes it can take 30 minutes.

While we associate yawning in humans with boredom or sleepiness, I’ve heard a few different theories about why fish do it. One is that they are stretching their mouths to be ready to feed  – kind of like flexing their muscles. Another is it is a sign of annoyance or warning, like “Hey you with the big camera – back off!”

Yawning Hairy Frogfish Ned DeLoach Blennywatcher.com

Is the frogfish yawning to flex its muscles or to threaten us?

While I was looking for information about fish yawning, I came across this cool site about yawning with everything you could ever want to know about the topic. It has a number of articles about yawning in fishes, including one that concludes it increases muscle tone, aiding in preparing the animal for action.

If you want to see yawning fish in action, check out this short video over at our Blenny Watcher YouTube channel

More Blennywatcher 2013 Favorites

Anchor Tuskfish, Choerodon anchorago, Ned DeLoach, Blennywatcher.com

Yep, we see those teeth! Anchor Tuskfish (Choerodon anchorago), Indonesia

Here are a few more favorite Blennywatcher images from 2013. If you are a regular reader of this blog, you will already have seen most of our favorite images, but some didn’t make into a post and others were published earlier this year in Alert Diver, Scuba Diving or Wetpixel. So, we’re ringing in the New Year with a few more photos from 2013, starting with this Anchor Tuskfish displaying quite a mouthful of teeth. The menacing look is quite out of character for this mild mannered member of the wrasse family.

 

Soft-coral Pipefish, Siokunichthys breviceps, Ned DeLoach BlennyWatcher.com

Even with the search image, the Soft-coral Pipefish were difficult to find and follow.

Our first trip of 2013 was a month long journey through Indonesia aboard the Dewi Nusantara that took us from Sorong up to Ternate then back down to Ambon. We were off to a grand start with a new fish for our life lists: the Soft-coral Pipefish, Siokunichthys breviceps. Cruise director Wendy Brown and our guide Yann Alfian had a newly acquired search image for the tiny pipefish and found a few right away on our first dive at Mioskon, setting the bar pretty high for the rest of the cruise.

 

Waigeo bay with jellyfish Bennywatcher.com

The serene bay in Waigeo was full of pulsing jellyfish.

Lagoon Jellyfish Waigeo, Ned DeLoach, BlennyWatcher.comOne of my favorite areas in the Raja Ampat region of Indonesia is the island of Waigeo and this time, Wendy surprised us with a snorkel trip in a small bay that is full of jellyfish. We spent an hour swimming (cautiously) with the lovely jellyfish and Ned, “Mr. Safety”, reported that they do not sting – he knew this because he tested it by putting his entire hand in the tentacles.

 

Waigeo wall with pitcher plants Anna DeLoach Blennywatcher.com

The walls were draped with orchids and pitcher plants

The steep walls that line the waterway to the bay are draped with blooming orchids and a climbing variety of the exotic pitcher plant, a carnivorous plant with a leaf that develops into a tendril that ends in the lidded pitcher. The plant secretes nectar that attracts insects into the trap below that is filled with digestive fluids.

 

Twotone Dartfish, Ptereleotris evides, Ned DeLoach Blennywatcher.com

The closer we got, the closer the dartfish hovered to the hole in the coral head.

Off Halmahera, we photographed this gathering of Twotone Dartfish, Ptereleotris evides (you can just see one Zebra Dartfish hanging out with them). We usually see this fish in pairs, hovering near sandy burrows. This gathering was unusual not only in number, but in the choice of burrow – a tall, nearly hollow coral head.

 

Blueringed Octopus Ned DeLoach Blennywatcher.com

The Blueringed Octo was on the move

This Blue-ringed Octopus had just emerged from beneath a green and brown crinoid and was in the process of changing color to blend in more closely with the reddish sponge.

 

Coral Croucher, Caracanthus maculatus, Ned DeLoach BlennyWatcher.com

I love the little hairy “wolfman” face of the Coral Croucher.

A two-inch Spotted Croucher, Caracanthus maculatus, peeks from within the branches of its Acropora coral home (Pisang Island, Indonesia).

 

Atlantic Longarm Octopus, Macrotritopus defilippi Ned DeLoach Blennywatcher.com

This was an extremely animated Atlantic Longarm Octopus.

Back in Florida, we managed two very quick trips to the muck-diving capital of Florida, the Blue Heron Bridge in Riviera Beach. Ned followed this Atlantic Longarm Octopus, Macrotritopus defilippi as it danced across the sand. I missed the action because I was obsessing over a pair of spawning Molly Millers (see Hello Molly).

 

Mock Hairy Blenny juvenile, Labrisomus cricota Ned DeLoach Blennywatcher.com

A one-inch juvenile Mock Hairy Blenny at the Blue Heron Bridge

As we were exiting from the dive, I stopped to check out the base of a bridge piling and saw a blenny that I did not recognize. I grabbed Ned to take this shot and sent it to Dr. Ben Victor for identification assistance. It turned out to be a juvenile Mock Hairy Blenny, Labrisomus cricota, originally described in 2002. The juveniles look very different from the adults.

 

Large-eye Toadfish Batrachoides gilberti Ned DeLoach Blennywatcher.com

The cartoon character face of a Large-eye Toadfish, Batrachoides gilberti

In July, we visited Utila in the western Caribbean for the first time. I prepared a “hit list” of species we wanted to photograph and with the help of the guides at Deep Blue Resort, found them all. This Large-eyeToadfish, Batrachoides gilberti, with its impossibly goofy face was quite a sight. We’ll be highlighting the rest of our finds in an upcoming Alert Diver Magazine article.

 

Circled shrimp Gnathophyllum circellum Ned DeLoach BlennyWatcher.com

Circled Shrimp on a Tiger Tail Sea Cucumber

Two summers ago in Bonaire, Bas Tol guided us on an East Coast night dive, where he showed us two Circled shrimp, Gnathophyllum circellum. We had never seen this shrimp any other time, but our friend Ellen Muller, sees them regularly on Bonaire and they had been reported them a few times from the Blue Heron Bridge. We finally found several on our own during a coral spawning night dive this past September during our annual stay at Buddy Dive – they were on Tiger Tail Sea Cucumbers! Their close relative, the Bumblebee Shrimp, is known to feed on the tube feet of echinoderms, so I wonder if the little Circle Shrimp were dining on the Tiger Tails or just along for a ride. (see Scuba Diving Magazine, Critter Hunt: Bumblebee Shrimp)

 

Christmas Tree Worm Spawning Ned DeLoach Blennywatcher.com

I saw it – I finally saw it – spawning Christmas Tree Worms!

After many years of looking for this, I finally saw spawning Christmas Tree Worms! This had become a bit of a joke among my friends as I always seemed to be in the wrong place at the wrong time when others saw it. This phenomenon has been observed at all hours of the day and night on many different moon phases, so predicting it was impossible. It was particularly maddening because the spawning is a slow process, lasting 15 to 20 minutes, so it is not like it would happen just as I looked away. I had resigned myself to never seeing it, then on coral spawning night, I lucked up! The way the eggs or sperm move slowly up and around the spirals of the feathery structures is slow and beautiful.

 

Ninelined Goby, Ginsburgellus novemlineatus Ned DeLoach BlennyWatcher.com

We always find Ninelined Gobies in association with urchins.

We devoted most of our month long Bonaire stay to hunting for blennies, which meant including visits to some of the generally less accessible dive sites in order to cover different habitats. At the southernmost end of the island, in 2 meters depth, we not only found blennies, but many species of gobies, including the adorable Ninelined Goby, Ginsburgellus novemlineatus.

 

Two-bar Triplefin, Enneanectes deloachorum in nuptial colors Ned DeLoach Blennywatcher.com

Two-bar Triplefin, Enneanectes deloachorum in nuptial colors

And wrapping up 2013, we were very pleased to learn that a blenny – the Two-bar Triplefin was named in our honor: Enneanectes deloachorum. This is a male in its nuptial colors. Dr. Ben Victor described the fish in the paper: The Caribbean Roughhead Triplefin (Enneanectes boehlkei): DNA barcoding reveals a complex of four West Indian sympatric cryptic species (Teleostei: Blennioidei: Tripterygiidae)This was indeed an honor and means a lot to us.

 

With that, we wish you happy diving, critter hunting and fishwatching in 2014!

Divers Back to the boat Ned DeLoach BlennyWatcher.com