Recently, during a get-together of diver friends, the subject of parrotfish cocoons came up – I don’t remember why – and surprisingly, several said they had never seen a parrotfish sleeping in a mucous cocoon. After thinking about it, Ned and I realized that in all the hundreds of night dives we’d made, we had only seen it maybe a half dozen times. We encountered it for the first time in the mid-90s off Key Largo while waiting for the coral to spawn. We didn’t see the coral spawn that night, but the parrotfish cocoon made our dive. Mucus, secreted from a gland below the operculum, enveloped the sleeping fish in a protective bubble. And until about four years ago, all I knew about this phenomenon was what was taught when I first started night diving: that the mucous cocoon prevented attacks from nighttime predators like moray eels, by masking the scent of the sleeping fish. That theory was proposed in the 1950s by the scientist (H.E. Winn) who originally described the mucous cocoon of parrotfishes.
In November 2010, marine researchers from the University of Queensland published their findings that proposed another theory behind the mystery of the fishy cocoons: the nighttime covering provides protections from blood-sucking parasites. In tests, when exposed to parasites, 95% of the fish not protected by cocoons were attacked while only 10% of those in cocoons were. They point out that this theory doesn’t have to be mutually exclusive with the moray eel predator theory.
Parrotfishes and some species in the related wrasse family sleep at night by bedding down directly on the sand or in holes in the reef, making them ideal targets for parasites that would have a more difficult time attaching to a swimming fish. Although we’ve only seen parrotfishes in cocoons, wrasses like the Bluestreak Cleaner Wrasse (Labroidesdimidiatus) and some in the genus Pseudocheilinus have been observed sleeping in mucous cocoons both in the wild and in aquariums.
I have posted a short video on our Blennywatcher YouTube channel or you can watch it below. (Note: We originally wrote about this in our June 2011 Critter Hunt column in Scuba Diving Magazine).
Meet Malacoctenus carrowi, a newly described blenny known from the Cape Verde Islands in the eastern Atlantic. A year ago, we announced a Blenny Auction to raise funding to enable Dr. Peter Wirtz to collect another specimen and complete the research to formalize the description of the fish, only the second species of the genus Malacoctenus to be known from the eastern Atlantic. As a result, the species has been named to honor Mr. Frank Carrow, whose interest in marine conservation led to his creation and funding of a foundation that supports a broad range of marine conservation activities. The paper, A new species of Malacoctenus from the Cape Verde islands, eastern Atlantic (Pisces Teleostei Labrisomidae)is available online. For more information about the books, publications and images of Dr. Wirtz, visit his web page at www.medslugs.de/E/Photographers/Peter_Wirtz.htm.
November, 2014 ~ If you have a photo of a blenny labeled Secretary Blenny, Acanthemblemaria maria, it is likely that you actually have a photo of a Spinyhead Blenny, Acanthemblemaria spinosa. A Google image search for “secretary blenny” produces pages and pages of images that are actually, with an occasional exception, Spinyhead Blennies. I have intimate knowledge of this problem — it has been wrong in Reef Fish Identification – Florida Caribbean Bahamas since the second edition (1994) and just sorted out in the recently published fourth edition of the book. Our field guides are written to help divers visually identify fishes in their natural habitat and even after 25 years, Ned and Paul still consider them to be works in progress, adding additional species and corrections, whenever practical, to new printings and editions. The Spinyhead Blenny – Punk/Christmas Tree Blenny – Secretary Blenny correction has been a long time in coming but with the help of Dr. Ben Victor the confusion has finally been cleared up.
A Google image search for “secretary blenny” yields mostly misidentified fish.
Figuring out how to visually tell the fishes of the genus Acanthemblemaria apart has long been an obsession of mine; I read scientific descriptions, examined Ned’s photos (first slides, then enlarged digital images) and experimented with various macro options on my video camera. Everything seems obvious on paper or the computer screen but underwater, in a surge, identifying a tiny, moving fish presents many difficulties. Along the way, I’ve learned some interesting things, including how the Secretary Blenny got its name. If you are only interested in the details of how to tell the two species apart, then skip down to the end of this post where there is also a link to a short video.
Spinyhead Blenny, Acanthemblemaria spinosa
Fishes in the genus Acanthemblemaria are small, tube-dwelling blennies, distinguished from other blennies in the family Chaenopsidae by the presence of spines on their heads and around their eyes. The spines are not to be confused with cirri – the fleshy stalks over the eyes and snout – or the papillae, soft protuberances, which are present on the heads of some of the acanthemblemariids (A. medusa and A. chaplini). The number, size and shapes of these spines, cirri and papillae are features that distinguish one species of the genus from another, but these features are usually so small that it is difficult to discern the differences without the aid of magnification and a very still fish. One of my all time favorite publications about blennies is Atlantic Fishes of the Genus Acanthemblemaria, with Description of Three New Species and Comments on Pacific Species (Clinidae: Chaenopsinae) by William F. Smith-Vaniz and Francisco J. Palacio. For years, I pored over the descriptions in this paper and obsessed over the illustrations of the cranial spines and cirri, but just could not match them with what we were seeing underwater on live fish.
About nine years ago, in an effort to establish a visual identification key for divers, we consulted Dr. Bill Smith-Vaniz. Under his direction, we obtained a collecting permit in Bonaire and collected a number of specimens of what we thought were Secretary, Spinyhead and Medusa blennies. Our friend Claire Davies helped us locate, photograph and collect the fishes. Our goal was to work out a key for fishwatchers, using Ned’s photos, matched to the positive identifications obtained from Bill’s examination of the collected fishes. But the results came back from Bill’s lab revealing that our collected fish were all Spinyheads and Medusas – not a Secretary in the bunch, even though we were certain we had collected some! That was important reinforcement that something was amiss in the visual identification of these fishes, but other projects took precedence and we set the question aside.
What people were calling the Punk is actually the Secretary Blenny
The next year, we visited St. Vincent, where we were shown the Punk Blenny, a reportedly undescribed Acanthemblemaria species that received its common name from the red flattop of spines on its head. In other areas, there were reports of a blenny that fishwatchers were calling the Christmas Tree Blenny, for its distinctive cirri. Around the same time, I saw a post in an online forum requesting help in determining whether a fish was a Spinyhead or Secretary Blenny and Ben Victor’s response, that the “CDs and books are wrong” and the Punk Blenny is the real Secretary Blenny. Ned and I finally had the opportunity to talk to Ben at length about the Secretary/Spinyhead confusion when he joined the ReefNet team and us for a two-week dive trip to Dominica in 2010 and we enlisted him to help set the record straight. Ben is both an ichthyologist and medical doctor who has conducted extensive research on larval fishes of the Caribbean (his site: http://www.coralreeffish.com ) and is familiar with the distribution of fishes based on collection records throughout the tropical western Atlantic. Ben confirmed that there is no such thing as a Punk or Christmas Tree Blenny. After asking around, I am pretty sure the Christmas Tree and Punk blennies were references to the same fish although it is possible that what people were calling Christmas Tree Blennies were actually Medusa Blennies (A. medusa).
Secretary Blenny (A. maria) stretches out of its hole.
While waiting for the publication of the fourth edition of Reef Fish Identification with its additional photos and corrected identifications, I decided to dig into the scientific literature about Secretary and Spinyhead blennies. The Spinyhead, Acanthemblemaria spinosa, was originally described in 1917 from specimens taken in Curacao. In 1928, William Beebe and John Tee-Van described Acanthemblemaria variegata. In 1941, this was temporarily made a synonym of, i.e., considered the same species as, the Spinyhead (A. spinosa) by Longley and Hildebrand. In 1957, James Böhlke published The Bahaman Species of Emblemariid Blennies, in which he summarized the Acanthemblemariids known to date in the Bahamas. In discussing the Spinyhead, he includes the work of both Beebe and Tee-Van (A. variegata) and Longley and Hildebrand and noted some differences in spine counts between his specimens and those described by Longley and Hildebrand indicating that, “It is possible that A. variegata is the true spinosa and the above specimens represent an undescribed species;”
Sure enough, in 1961, he published, The Atlantic species of the clinid fish genus Acanthemblemaria, in which he sets the record straight, that A.variegataBeebe and Tee-Van is actually A. spinosa - the Spinyhead originally described in 1919 – and the blenny that was troubling him in his 1957 paper was in fact a new species, Acanthemblemaria maria, which he “Named for Mrs. Mary George, my secretary for the past five years and now parent and housewife, in appreciation of her assistance in all the activities of the department during that period.” So the new blenny was named to honor to Dr. Böhlke’s secretary, Mary George, hence the common name, Secretary Blenny (I love little tidbits about how fishes are named – see my Arrow Blenny post). I’ve heard suggestions that the common name should just be changed to Punk Blenny, but in deference to Dr. Böhlke and Mary George, I truly hope that never happens. The name “punk blenny” just adds to the confusion and should be dropped completely.
So to summarize: If you have a picture of a Punk or Christmas Tree Blenny, it is most likely a true Secretary Blenny. If you have a blenny photo labeled Secretary Blenny, check it again to make sure it isn’t really a Spinyhead Blenny. Both species have similar markings, including spots on their lips (except the Bahamas, where Secretaries’ lips have lines – note from Ben Victor). Spinyheads tend to have many uniform, short head spines, while Secretaries have fewer that are larger. The differences in their cirri are very difficult to see with the naked eye. The Secretary Blenny has a very distinctive orange patch over the back of the head, tends to be larger than Spinyheads and we have always found them in areas of high-energy or surgy water and rarely below 25 feet. Ben also notes, “There are no records of Secretary blennies in Florida or Bonaire. There are no records of Spinyheads in Florida or Panama.”
Banda Sea, April 2014 ~ This algae covered decorator crab, found by Ned on a night dive off Pantar, Indonesia, is one of my favorite images from our April trip around the Banda Sea. We boarded the Dewi Nusantara in Ambon and dived our way down through and around the southern perimeter of the Banda Sea and across through the Alor region, ending in Flores. And oh, what a trip!
Last year, I posted about the little bryozoan goby that Graham Abbott found in Ambon. We looked for it all the way down from Halmahera to Ambon, but only found it in Ambon at the end of our cruise. This year, our trip started in Ambon, so we searched for it as we traveled south but didn’t find it until we reached Alor. After we blogged about it last year, the fish became quite an attraction with the dive operators in Ambon and I shared information about how to find these tiny, cryptic fish with others. I am pleased to say that one of them found the goby in Lembeh a few months ago, so it is now known from Ambon, Alor and Lembeh. I can understand Ambon and Alor, but I find it interesting this fish wasn’t seen earlier in Lembeh, a muck diving mecca visited by thousands of divers. Just shows how knowing something exists can often be the key to more sightings.
Another fish that we have been searching for is Cirrhilabrus humanni, a fairy wrasse I discovered in 2010 off Pura Island and formally described by Dr. Gerry Allen in 2012. During our 2010 trip, I only saw the one male with a harem of many females so we were keen to know more about its range. This time our friend, Dr. Richard Smith, was the first to find one. Alerted to its presence by Richard, we found a couple more on the dive site off Alor. Richard’s wonderful shot is posted on his site, Oceanrealmimages.com.
I have seen many Midas Blennies, but never one in its courting colors. The banded pattern caught my attention but it took a while to realize which blenny it was because it was so large. I pestered Ned until he went back with me to take photos. One shallow outcropping sported a highly motivated population of at least eight males.
On an early morning dive, our guide Yann pointed out Red-margined Wrasse, also flashing bright courting colors.
I found this stunner, a flasher wrasse (possibly undescribed), on a late afternoon dive and finally got the attention of Ned, our guide Yann and our friend Dave Dempsey, who were equally impressed! We were able to return the next day so everyone else could see these beauties.
Night dives almost always yield fabulous creatures like this bumblebee shrimp perched on a brightly colored sea apple. Bumblebee shrimp feed on the tube feet of echinoderms, which is why we often find them on sea cucumbers and urchins.
You can get an idea of how small this Bobtail squid is by comparing it to the shrimp it is holding. Ned shot this photo as the squid was capturing its dinner.
Who can resist a teddy bear? During a mucky night dive, Ned found this Teddy Bear Crab out bimbling around. I touched it – couldn’t resist – it was so soft.
It is hard to believe that this tiny Pinnate Batfish grows up to be a large, rather nondescript silver-gray fish.
This cuttlefish was not impressed with Ned and his camera. Here, it exhibits what I think is a threat display.
It isn’t uncommon to see Fire Dartfish singly or in pairs, but just outside of Banda, I found a group of almost 20! True to their name, they darted into their holes when we approached but Ned caught a respectable number in his shot.
We close with happy bees of Banda – we had a lovely morning walking tour of a nutmeg plantation and fort on Banda Neira.
Recently, during a get-together of diver friends, the subject of parrotfish cocoons came up – I don’t remember why – and surprisingly, several said they had never seen a parrotfish sleeping in a mucous cocoon. After thinking about it, Ned and I realized that in all the hundreds of night dives we’d made, we had only seen it maybe a half dozen times. We encountered it for the first time in the mid-90s off Key Largo while waiting for the coral to spawn. We didn’t see the coral spawn that night, but the parrotfish cocoon made our dive. Mucus, secreted from a gland below the operculum, enveloped the sleeping fish in a protective bubble. And until about four years ago, all I knew about this phenomenon was what was taught when I first started night diving: that the mucous cocoon prevented attacks from nighttime predators like moray eels, by masking the scent of the sleeping fish. That theory was proposed in the 1950s by the scientist (H.E. Winn) who originally described the mucous cocoon of parrotfishes.
Banda Sea, April 2014 ~ This algae covered decorator crab, found by Ned on a night dive off Pantar, Indonesia, is one of my favorite images from our April trip around the Banda Sea. We boarded the Dewi Nusantara in Ambon and dived our way down through and around the southern perimeter of the Banda Sea and across through the Alor region, ending in Flores. And oh, what a trip!
