Bird’s Head Seascape – Natural History Notes (PT5: Raja Rarities)

Bird’s Head Seascape – Natural History Notes (PT5: Raja Rarities)

The Bird’s Head Seascape is often touted as the epicentre of global marine biodiversity, and its reefs are truly something to behold. It is undoubtedly one of my favourite places on the planet to dive, and I am still amazed that every time I visit I encounter creatures I’ve never seen before. Some are new to science, others are way outside their previously known geographic range and yet more are hitherto known from just a few specimens. However, you might be surprised that it can take a little time to fall in love with this place.

With all the superlatives associated with Raja Ampat, expectations are always high but when folk arrive from across the world they can sometimes seem confused what all the fuss is about. Of course, there are a lot of fish, yes the reefs are pristine but the visibility isn’t always gin clear and there were only two pygmy seahorses on that last dive! Personally, I think that the Bird’s Head isn’t a one visit kind of place. A first visit can easily be spent looking at the bigger picture, distracted from the reef’s smaller inhabitants. You might not get to both the north and south of Raja, which are so very distinct from each other. You might not be there in the season that great clouds of silversides smother the reef. There are so many facets to the Bird’s Head that you simply can’t see it all on one trip.

Something very special about the Bird’s Head is the unexpected rarities that you are sure to encounter given time. On a previous Natural History Notes, I shared my discovery of a leopard anemone shrimp pair (Izucaris masudai) in north Raja. These stunning monochrome crustaceans were nonchalantly and unexpectedly sitting on a leopard anemone at 30 metres. On the same trip, I had photographed a Cenderawasih Bay fairy wrasse (Cirrhilabrus cenderawasih) off Batanta Island, one of Raja’s Four Kings. Named as recently as 2006, it turns out these beautiful fish aren’t restricted to the Bird’s Head’s famed northern bay as we first thought, they’re in Raja Ampat too.

Cenderawasih fairy wrasse spotted for the first time in Raja Ampat

Several years before, I was diving a great site in the north of Raja Ampat, named Cendana Dock where I found a couple of fishes that I hopefully named ‘Richard’s waspfish’. Howveer, thanks to Gerry Allen and Mark Erdmann’s fantastic ‘Reef Fishes of the East Indies’ apps, I finally discovered that it was in fact a rare triplefin velvetfish (Neoaploactis tridorsalis) known from just a few scattered locations in the Coral Triangle.

A rare triplefin velvetfish in very shallow water in northern Raja Ampat

Another fish that this app had finally helped me to identify was a bright green frogfish that I found at night on the Kri House Reef on my first visit to Raja Ampat in 2004. When I saw it again in Aljui Bay, North Raja, I solved the mystery and figured out its identity as the marble-mouthed frogfish (Lophiocharon lithinostomus). Again, a distinctive fish known only from scattered locations in the region.

Marble-mouthed frogfish are a rare species found in certain areas of Raja Ampat

For nudibranch lovers, the Bird’s Head again can easily take you by surprise. This spring, on a dive off Batanta Island I found a rare and very variable nudibranch, the pitted Ceratosoma(Ceratosoma miamiranum). The mantle edge had a harsh zippered edge and it took some time for me to find it in the identification books as some animals can be completely smooth and are almost incomparable. On a site in the south, I saw my first ornate dermatobranchus (Dermatobranchus ornatus). Unlike most members of this genus, this was a large animal several inches long. I always find it satisfying seeing a new nudi that isn’t too tiny to identify!

A stunning nudibranch Ceratosoma miamiranum

With each visit to the Bird’s Head one spends more time, covering more ground and looking even closer at the jubilant communities. Earlier this year, I was leading a group liveaboard tour around Raja Ampat. At a site called Mioskon something different caught my eye. From inside one of the large gaudy Polycarpa tunicates, I felt something following my progress along the reef. I looked round, and peering from within the exhalent siphon a large orange amphipod looking out. I had never seen anything like it. I later contacted the scientist who described a very similar species recently named after Sir Elton John, who explained that this is either a commensal amphipod, or a new species. He told me that this large male, with his menacing scythe-like gnathopod arms was likely guarding his partners and offspring within. Clearly, a great example of the Bird’s Head offering up another surprise.

An amphipod hiding inside a tunicate

Below are a few “Rarities” photos that aren’t mentioned in the text which Richard would like to share with us. Thanks Rich!

A paddle flap Rhinopias was an unexpected discovery off Batanta Island

Big-lip damselfish are the Angelina Jolie of the fish world

Miniature clingfish in southern Raja Ampat

Links to Previous Blogs:

PART ONE | In Appreciation of Damsels

PART TWO | Craving Cryptic Crustaceans

PART THREE |Sinister Hitchhikers

PART FOUR | The Pygmy Seahorses of Raja Ampat

PART FIVE | Raja Rarities

Richard Smith PhD, a British underwater photographer and writer, aspires to promote an appreciation for the ocean’s inhabitants and raise awareness of marine conservation issues through his images. A marine biologist by training, Richard’s pioneering research on the biology and conservation of pygmy seahorses, led to the first PhD on these enigmatic fishes. Over the past decade, Richard’s photographs and marine life focused features have appeared in a wide variety of publications around the world. Richard leads expeditions where the aim is for participants to get more from their diving and photography by learning about the marine environment through marine biology lectures: www.OceanRealmImages.com / Facebook.com/OceanRealmImages

Originally written for BirdsHeadSeascape.com Science & Conservation Blog
Richard Attends a Seahorse Biology Conference

Richard Attends a Seahorse Biology Conference

Something that I’ve been looking forward to for almost a year now is the SyngBio conference.  Last week I was at the University of Tampa on the west coast of Florida to attend the meeting, which was the third of its kind.  Researchers, zoo aquarists and other professionals from around the world, who work with syngnathids (Seahorses, pipefishes and their relatives), formed the 100 plus attendees.

Although I attended the full four days of lectures and seminars, I was invited as a keynote speaker at the ‘Scientific Storytelling’ evening event that was held at The Florida Aquarium on Monday 15th May.  Besides floating around on a boat in remote Papua, it was probably one of the most amazing places I have ever done a talk.  My podium was directly in front of a huge aquarium window, with sand tiger sharks, huge turtles and moray eels all going about their business behind me.

It has been a few years since I finished my PhD ‘The Biology and Conservation of Gorgonian-associated Pygmy Seahorses’ but the highlight of the SyngBio conference was finally meeting the researchers that I’d cited so many times during my work.  Honestly, I was a little intimated to meet some of them.  Forget those Kardashian folk, these people are real celebrities!  In reality, I have rarely met such an amazing bunch of people.  The collective drive and passion was truly inspiring.  There are sure to be some interesting projects that will come from the meeting, which I know was the motivation for getting the world’s syngnathid researchers together initially.

Apart from my talk, the other main reason for my visit to SyngBio was to attend the first meeting of the IUCN Seahorse and Pipefish Specialist Group, which was formed last year.  This group is part of the Species Survival Commission and, as the global authorities on these fishes, the group’s main aim is to ensure that their wild populations are healthy and well-managed.  I was very honoured to be invited to join this small group of fifteen or so members last year.  We gathered on the fifth day of the conference and worked on putting together a Species Action Plan for these animals.  The fruits of that will become available over the coming months.

I was very kindly sponsored to attend SyngBio by the HW Hoover FoundationProject Seahorse and a donation from
our own Our Beloved Seas (Wendy and I always donate to a conservation organisation from our trips).

Please stay posted for updates via my Facebook page or here.  If you’re a diver and want to help, you can register any of your seahorse sightings around the world through iSeahorse, more here.

Bird’s Head Seascape – Natural History Notes (PT4: The Pygmy Seahorses of Raja Ampat)

Bird’s Head Seascape – Natural History Notes (PT4: The Pygmy Seahorses of Raja Ampat)

For many people, one of the main attractions of the Bird’s Head Seascape is the pygmy seahorse (well I like to think so at least).  Certainly, Raja has amongst the highest density and diversity of these diminutive fishes on the planet.  If you haven’t seen one yet, they almost defy belief. It is easy to list any number of unusual features about them: a horse-like head ending in a puckered mouth, a monkey-like prehensile tail and eyes that move about independently.  From the tip of its pug-like snout to the tip of its stretched out tail, the largest can only just reach across a US quarter.  Even stranger than all of this is their reproduction where extraordinarily devoted fathers become pregnant and strict monogamy is exhibited between life-long partners.

I was recently on a trip exploring Raja Ampat aboard the Arenui, joining a cruise as resident pygmy seahorse expert.  Several years ago, I completed the first research on the biology of pygmy seahorses for my PhD thesis and was excited to spend a trip dedicated to these miniature fishes.  Five of the six described species of pygmies have been named since the turn of this millennium, which explains why there has been so little research on them.  During the trip aboard Arenui, I gave a series of lectures about my findings and the area’s astounding marine life in general.  We were lucky to see three of the area’s four species during the trip and there was great engagement from the guests who enjoyed hearing of the soap opera-like social lives of pygmies.

Pygmy Seahorses of the Bird’s Head Seascape:

Bargibant’s (Hippocampus bargibanti)| Bargibant’s pygmy was the first species to be discovered.  A researcher at the Noumea Museum in New Caledonia accidentally found the first pair when he collected a gorgonian coral for the museum’s collection.  The species was named after him in 1970, but divers weren’t regularly seeing them until the 90’s.  Bargibant’s pygmies only live in association with Muricella gorgonians and are covered in tiny bumps that mimic the coral’s closed polyps.

Denise’s (H. denise)| This is another gorgonian-living, and commonly seen species in Raja Ampat.  They can be distinguished from the closely related Bargibant’s species, by their more slender shape and longer snout.  They are also much more cosmopolitan than Bargibant’s: so far I have found them living on ten different types of gorgonians.  As a result of them inhabiting such a variety of habitats, their colours and surface textures are much more variable than Bargibant’s.  I have seen various hues of yellow, red, pink and even white.  Raja Ampat is also known for an, otherwise rare, red and white variety that inhabits Melithaea gorgonians.

 

Pontoh’s (H. pontohi)| In 2008, the two species of free-living white and brown pygmies were given the names, Hippocampus pontohi and H. severnsi respectively.  However, it appears that scientists may have jumped the gun.  Genetic evidence has since shown that they actually represent two colour forms of a single species.  The name ‘Severn’s’ is being dropped and Pontoh’s will be retained into the future.  Like many seahorses, this new evidence shows just how much variability there can be within a single species of seahorse.  Camouflage is so important to pygmies that they generally match their surroundings very closely.  White ones are most often seen around Halimeda algae, and brown ones around hydroids.

Satomi’s (H. satomiae)| This is the least common of the Bird’s Head’s pygmies, and in fact is currently only known from Indonesia.  It is also the smallest pygmy, not even reaching across a dime.  Very little is know about this species, but it seems to become active around dusk and is generally found slightly deeper than the other free-living species.  When I have seen them, they’ve often been attached to soft corals and hydroids beneath a large over hang.  There are beige and dark brown colour forms, and all are very active swimmers.

Photographing Pygmy Seahorses:

Sometimes it can a bit of a double-edged sword leading a trip that encourages people to interact with and photograph pygmies. I am always very keen to encourage non-invasive interactions where we can enjoy and capture images of them, without causing stress or harm.  The take-home messages I hope to promote are there should be absolutely no touching of the pygmy or their gorgonian, and to limit the number of strobe-lit images.  In fact, this subject was part of my PhD research and the findings are available as a code of conduct document that helps us to avoid certain behaviours that cause direct stress to the fish.

Recording your observations:

Relatively recently Project Seahorse, the world’s largest seahorse conservation organisation, began a citizen science initiative called iSeahorse.  This is designed primarily for who are able to record their seahorse sightings.  This includes pygmy seahorses, and the big ones too.  Next time you are diving and spot a seahorse, please record and log your observation.  You can check out the website to learn about the kind of information that is valuable to them.  I used iSeahorse to register my find of a Bargibant’s pygmy near Tokyo, which extended their known geographic range by hundreds of miles northwards.

Raja Ampat is one of the few pleases where you can see four of the six species of pygmy seahorse.  It’s hardly surprising, given the extraordinarily high biodiversity of the area and it’s fantastic level of protection.  Just remember, whilst enjoying pygmy seahorses please ensure not to disturb them.

Links to Previous Blogs:

PART ONE | In Appreciation of Damsels

PART TWO | Craving Cryptic Crustaceans

PART THREE |Sinister Hitchhikers

PART FIVE | Raja Rarities

By Dr Richard Smith | Originally written for BirdsHeadSeascape.com Science & Conservation Blog

Bird’s Head Seascape – Natural History Notes (PT3: Sinister Hitchhikers)

Bird’s Head Seascape – Natural History Notes (PT3: Sinister Hitchhikers)

Parasites permeate every corner of the animal kingdom; indeed, even parasites have their own parasites. With one of my PhD colleague’s research focusing on coral reef fish parasites I started to pay more attention to these sinister members of the community.  Now I can hardly do a dive without coming across a stricken fish or other reef creature that is suffering at the hands of one of these insidious but fascinating beasts.

Funky Pill Bugs

Sweeper fish with parasite on headSweeper fish with parasite on headIn January this year I was aboard Dewi Nusantara for my charter exploring Raja Ampat’s southern reaches and the island of Kofiau.  As always, I gave lectures about the area’s marine life, so my regular guests are well aware of my penchant for external parasites.  Several even come up from their dives regaling me with stories of how many they’ve seen: there is a funny ecological quirk whereby if one fish is infected often a large proportion of the same species locally also will be.  According to my colleague, this is because these parasites ‘burst’ spawn and their offspring will infect many other individuals around the same area.

Parasites are extremely common on coral reefs.  Some bite and gorge themselves on blood very rapidly then drop off, whilst others grip on their host for their whole adult life.  The external parasites that have been the focus of my natural history notes of late are isopod crustaceans, which are basically marine pill bugs (woodlice for the Brits, or sea lice to anglers), found in the family Cymothoidae.  They are extremely species and site specific, usually found in the exact same location on just one host species.  Some attach themselves externally to scales, others are flesh burrowing (I saw some of these in temperate Australia recently, and they made me feel quite queasy), some attach to the gills and others live in the fish’s mouth.

Not Forgotten

Fusilier with chin parasite. Raja AmpatFusilier with chin parasite. Raja AmpatMost recently, amongst one of the enormous schools of passing fusiliers at the dive site ‘Boo Windows’, something caught my eye under one of the fish’s chins.  When I was able to get a closer look at a cleaning station I saw that the stricken fish had a huge white isopod parasite clutching to the underside of its head.  It had obviously been there sometime, as the fish was slightly deformed where the parasite’s little legs were latched on.  There was even a groove for the parasite to rest.

Whilst many of these copepod parasites are dark in colour, I was interested to see that this one was white.  Fusiliers’ type of colouration is known as countershading, whereby their belly is paler than their dorsal surface.  This helps to camouflage them against predators from above, as their dark top-half acts as camouflage against the darker water below.  Contrastingly, the pale belly camouflages them against predation from below against the predators looking up at the bright sky.  The parasite appears to have followed suit and matches the fish’s paler ventral colours.  Through natural selection, one would assume that fish carrying dark parasites would more likely be eaten than those carrying pale chin parasites.  The pale parasite is less likely to draw the attention of their host’s predators.  Since this would also mean that the parasites too are less likely to be eaten and are thus able to pass on their genes, eventually a pale parasite has prevailed.

I was intrigued to see only one isopod living under the fusilier’s chin, but in one of my images I discovered that there was actually another smaller individual living under the larger one.  The bigger of the two is the female, and the tiny one beneath is the male.  Since he is hidden under the large female’s tail, he is dark grey in colour.  After mating, the eggs of cymothoid isopods develop in a pouch on the female’s body.  There the young hatch and undergo their first moult.  The active and agile young then leave the brood pouch and go in search of a host of their own.  They have well-developed eyes, helping them to track down a host.  Between leaving the mother’s pouch and making permanent attachment on their new host, they undergo several moults.  Each stage is perfectly adapted for the job the larva needs to complete.  Sensory structures come and go and at the last stage grasping claws appear, which help their final attachment to the host.

Shrimp with internal isopod parasite

These isopod parasites are common on the reef and infect many different fishes; however, they are not only limited to fishes.  There are certain species that also inhabit the gill arches of crustaceans.  Whilst they look punishing for the host, parasites generally don’t kill them.  They can cause lesions, reduced their growth rates and make them weak and more prone to illness or predation, but the parasite wouldn’t actually benefit from the host’s demise – they’d lose their home.  Some parasites have extremely sinister tricks up their sleeve to ensure that they alone are looked after.  Certain parasites are able to sterilise their host, so the host producing its own offspring does not waste vital energy.

Next time you are diving in Raja Ampat, I suggest you keep you eyes peeled for these sinister hitchhikers living on the reef’s creatures.  Unsurprisingly, there are more species of these parasites in the Coral Triangle region than anywhere else on Earth.  After all, they too help add to the extraordinary number of species that make coral reefs one of the most biodiverse ecosystems on the planet.

 By Dr Richard Smith | Originally written for BirdsHeadSeascape.com Science & Conservation Blog

Links to previous blogs:

PART ONE | In Appreciation of Damsels

PART TWO | Craving Cryptic Crustaceans

PART FOUR | The Pygmy Seahorses of Raja Ampat

PART FIVE | Raja Rarities

Bird’s Head Seascape – Natural History Notes (PT 2: Craving Cryptic Custaceans)

Bird’s Head Seascape – Natural History Notes (PT 2: Craving Cryptic Custaceans)

Raja Ampat is famed for its outstanding fish diversity, so it’s sometimes forgotten that the area’s species richness extends beyond the piscine delights.  Although I would probably count fishes as my first love, I have a lot of time for crustaceans, and there’s usually a shrimp or crab of some kind that I’m hunting for during a trip.  At the heart of the Coral Triangle, I knew that the Bird’s Head’s high biodiversity would make it a great place to seek my latest target, the giant clam shrimp.  So, on my recent trip aboard Dewi Nusantara, I spent many hours scouring these massive molluscs for their miniscule residents, leading me to ponder the region’s other crustaceans too.

Specificity

Coleman's shrimps from Raja AmpatCoral reefs are well known for the huge numbers of species they accommodate.  One of the reasons the biodiversity of a reef is so high are the close interrelationships between different species.  Most are very closely associated with just one species. Spotted and spiny porcelain crabs for example live only with certain anemones, Coleman’s shrimps live only with fire urchins, whip coral shrimps obviously live on sea whips and new examples are discovered all the time.  A few years ago, Ned and Anna DeLoach continued their legacy of discovery by finding a type of porcelain crab that lives only on the anemones that live on the shells of certain hermit crabs!  This level of union blows my mind, but is commonplace in Raja Ampat and the Coral Triangle.

Not Forgotten

When we talk about crustaceans, we automatically think of shrimps and crabs, but the group is in fact much larger, with many of the less well-known groups often going unnoticed.  For example, the isopods that stick to and feed on the blood of hapless fishes are a kind of crustacean.  One, the tongue-biter cymathoid isopod, lives in a fish’s mouth killing off its tongue and drinking its blood.

Four whip coral shrimpsDuring my most recent trip in Raja Ampat, unusually strong winds from the south prevented us from getting to a few of the sites we usually visit; however, it gave us opportunity to explore some rarely visited northern locations.  We headed to a small bay, not many miles south of the equator.  Here, as soon as we descended, there were great clouds of colonial pelagic tunicates, or salps.  This is unusual in itself, but these salps were accommodating an even more interesting companion.

Sea sapphires are yet another kind of copepod crustacean.  They’re often mistaken for falling fish scales in the blue water, but this iridescent shimmering is actually light reflected from the crystalline structures on their backs.  Only the males have this reflective surface, which is used to attract females that live inside the salps.  With so many salps in the area, there were a huge number of these sea sapphires too.  I found one that had a female and half a dozen male sea sapphires clustered within.  Since the males are usually free-swimming they had almost certainly entered the salp to mate.

Unusual Sightings

Cardinalfish with copepod parasiteRaja Ampat is so rich in terms of its marine life that it’s unsurprising to come across very rare and unusual crustaceans.  Over the years I’ve found harlequin and tiger shrimps, rarely seen cryptic sponge shrimps and thorny crinoid crabs amongst many others.  Recently my hunt for the giant clam shrimp was very fruitful and I saw quite a few of these scarcely photographed shrimps all around the region.  Obviously living in close association with giant clams, they are not at all easy to photograph.  Not only are they skittish and elusive, but their clam home is so sensitive to any localised water movement that is takes a great deal of patience and perseverance to find them.

These weren’t the only shrimps that I saw for the first time on this trip.  Another, the leopard anemone shrimp, is one that I’ve been hunting for years. As their name suggests, they live only on leopard anemones.  Stunning in their own right, these small colonial anemones are just a few centimetres in length themselves, so their tiny and amazingly well camouflaged shrimps are extraordinarily hard to find.  Thinking to myself, “Wouldn’t it be lovely if this anemone had one of those shrimps”.  I was shocked when it actually did.  Well, initially shocked but then I remembered I was in Raja Ampat where anything goes.

Links to Previous Blogs:

PART ONE | In Appreciation of Damsels

PART THREE |Sinister Hitchhikers

PART FOUR | The Pygmy Seahorses of Raja Ampat

PART FIVE | Raja Rarities

By Dr Richard Smith | Originally written for BirdsHeadSeascape.com Science & Conservation Blog

BIOGRAPHY: Richard Smith, a British underwater photographer and writer, aspires to promote an appreciation for the ocean’s inhabitants and raise awareness of marine conservation issues through his images.  A marine biologist by training, Richard’s pioneering research on the biology and conservation of pygmy seahorses, led to the first PhD on these enigmatic fishes.  Over the past decade, Richard’s photographs and marine life focused features have appeared in a wide variety of publications around the world. Richard leads expeditions where the aim is for participants to get more from their diving and photography by learning about the marine environment through marine biology lectures: www.OceanRealmImages.com | Facebook.com/OceanRealmImages