Bird’s Head Seascape – Natural History Notes (PT 1: In Appreciation of Damsels)

Bird’s Head Seascape – Natural History Notes (PT 1: In Appreciation of Damsels)

Damselfishes are a ubiquitous, but often overlooked, member of the Indo-Pacific reef fish community.  Around two hundred and fifty species, three quarters of the world’s damsels, are known to live in the Indo-West Pacific.  With the world’s highest marine biodiversity, where better to enjoy these fishes first hand than Raja Ampat?

Spawning blue green chromisDamselfishes are egg layers, most often laying their clutch on a pre-prepared nest site somewhere on the reef.  When their eggs hatch, the majority of species’ fry will immediately be swept off in the currents to disperse around the ocean.  Whilst the parents of these young fishes will never see the fruits of their reproductive endeavours, others raise young that never seem to leave home: the ‘Gen Y’ of the fish world. Over the past eleven days, I have been exploring the northern islands of Raja Ampat aboard Dewi Nusantara observing this unassuming group of fishes and their array of reproductive strategies.

Ecosystem Engineers

Many of us have had personal experience of a damselfish protecting its eggs.  Sergeant Majors, anemonefishes and golden damsels are amongst a few of the common damsels that will not hesitate to take on us bubble blowers, seemingly unperturbed by our comparatively massive size.  These demersal spawners, lay their eggs directly onto the substrate.  Sergeant Majors nest en masse, with dozens of individuals making a wasteland of a few square metres of the reef, laying their purplish spawn that they enthusiastically protect from marauders.  As such they are a kind of ecosystem engineer, altering the habitat for their own benefit but changing it for others too.

Spiny Chromis parent with frySpiny Chromis parent with frySwimming along a reef in northern Batanta Island, I came across a honeyhead damsel that had also strikingly altered its local environment.  Rather than denuding it to lay its eggs, it had encouraged verdant algal growth within the square metre or so of its territory that it enthusiastically warded me away from.  Like a disgruntled farmer it chased off any other creatures that tried to enter the confines of its little farmyard.  Within the allotment honeyheads farm filamentous algae, which act as their primary food source. Their agricultural proclivities, and the exclusion of other herbivores and corallivores, alter the composition of species within these plots.  By changing patches of the reef, these damsels are altering it for other species too. Their influences having a disproportionately large reach given their size.

Golden damsels on the other hand, usually lay their clutch of bright pink eggs on a whip coral or some other such protuberance coming off the reef.  You’ll often see the diligent parent tending to their clutch.  By aerating and removing infertile or spoiled eggs, they remove a reservoir of infection for others in the clutch.  Like the eggs of many fishes, the initially vivid fresh eggs soon become grey in colour as they mature and the fry develop within.  Just prior to hatching you can even see the reflective eyes of the tiny fish within.

Doting Parents

Juvenile spiny chromisOne of the more extreme parental investments of a damselfish is found in spiny chromis.  These inconspicuous damsels lay few large eggs, which both parents tend for an extended period until the relatively large fry hatch.  They are rare amongst reef fishes, in that the fry lack a pelagic larval stage and remain close to where they were born their entire life.  Although adults aren’t as protective of their fry as some other damsels, they keep an ever-watchful eye over the brood from hatching until they are quite large in size.  When small the fry are almost transparent, but take on a faint yellow stripe as they grow.  Adult spiny chromis have quite pointed fins and although variable in colour geographically, they are more often than not dark in colour, especially in the West Papua region.  Finally the youngsters darken to become miniature versions of their parents, and even at this late stage remain in a loose school casually overseen by their parents.

Changing Colours

A final quirk of damselfish reproduction, which for me makes them one of the most beautiful reef fish groups, is the diversity of their juvenile forms.  Adult black damsels, for instance, are midnight black in colour whereas their juveniles are almost indistinguishable as the same species.  They are unexpectedly white and bright yellow, with bluey black ventral and anal fins.  The leading theory for the dramatic change in colour or pattern from juvenile to adult in reef fishes is to reduce territorial aggression from adults.  If juveniles appear completely different, the adults are less likely to hound them out of their territory and the two can coexist amicably.

Damselfishes are a group that many divers seem to overlook.  I hope that I’ve convinced you to spare these unassuming fishes a thought on your next visit to the Bird’s Head. The more you learn about these abundant fishes the more fascinating they become, adding both to the diversity of the region and your diving experience.

Links to Previous Blogs:

PART TWO | Craving Cryptic Crustaceans

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

Ocean Realm Images FLOW – Newsletter 2015

Ocean Realm Images FLOW – Newsletter 2015

I really don’t know what happened to 2015, but what a great years it’s been! There have been lots of amazing expeditions, creatures and publications to my name.  I hope you’ve all had a brilliant 2015 and looking forward to 2016 and beyond.  Here’s is a little run down of what I’ve been up to over the past 6 months:

Completed Trips

Leopard anemone shrimpApart from some non-group expeditions, in the six months since my last blog I’ve run trips to Atlantis Dumaguete Resort and aboard Atlantis’ Azores liveaboard around Cebu Island in the Philippines.  Most of the guests joined us for the entire 18 days and we saw such amazing creatures as 18 seahorses on one dive, 11 frogfishes on another, thresher sharks, whale sharks, Lembeh seadragons (Kyonemichthys rumengani) plus many more.  As always, we donated some of the proceeds from the trip to a conservation organisation.  In this case we chose the Marine Megafauna Foundation, who strive to protect the world’s biggest marine fishes.

Lynne's pipefishJust recently also I completed a trip aboard the Bilikiki in the Solomon Islands.  I am always blown away by the remoteness of the Solomons. The reefs are pristine and full of life, whilst on land, we went to a village that had never been visited by foreigners in the 60 years since it was founded.  I can’t imagine that’s true of many places in the world these days.  My underwater highlight was certainly Lynne’s pipefish (Festucalex rufus), which I have been looking for for sometime but had never seen before.

 

Upcoming Trips

I have recently added four brand new expeditions to the 2018 roster.  I know this seems terribly far away, but time flies! Our 2016 is basically full and 2017 is going the same way, so we figured it was time.  There are more details about trips below, alternatively keep an eye on my website, which I keep up to date: OceanRealmImages.com/Expeditions

2016 | I’ve been very fortunate with my trips filling up very quickly and there are only a couple of spots remaining to join my expeditions in 2016.  These last spaces are on the trip I’m leading for Dive Worldwide to Atmosphere Resort, Dumaguete in the Philippines.  To read more about this expert led ‘Dumaguete Dive Festival‘ please follow the link above or contact Reservations@DiveWorldwide.com

2017

2-12th March 2017 (10 nights) | All of Raja Ampat, West Papua, Indonesia.  Indo-Siren Liveaboard. ‘Four Kings Expedition‘ as an expert led group tour for Dive Worldwide.  For more information please follow the link
above or contact Reservations@DiveWorldwide.com

23rd June – 3rd July 2017 (10 nights) | Underwater Photography Workshop at Siladen Resort, North Sulawesi, Indonesia. For more information please follow the link above or contact Ana@Siladen.com

Giant clam dottybackNEW | 22 – 31st August 2017 (9 nights) | Muck Magic Trip 1 – Sangeang Island & Bima Bay aboard Damai II (Labuan Bajo to Bima).  This ‘Our Beloved Seas’ trip is a joint trip between Wendy Brown and myself.  We have recently added this and the trip directly following it, but the second trip filled in minutes! If you’d like to join us in these exceedingly rich and rarely visited areas for critter hunting please contact Wendy or myself(Richard@OceanRealmImages.com) for more information. We expect space to fill fast.

 

2018

Hammerhead sharks in Galapagos IslandsNEW | Galapagos Islands aboard Galapagos Sky

25th February – 4th March 2018 (7 nights) | Trip 1

4-11th March 2018 (7 nights) | Trip 2

Wendy and I have repeatedly been asked by our guests to plan some trips to destinations outside the Coral Triangle. However, knowing how our regular guests love that area’s warm waters we have planned back to back trips to the Galapagos Islands in February/March when the waters of these mystical and historic islands tends to be warmer and clearer – whilst maintaining their renowned bounty.  As always, I’ll be giving talks and this will be the perfect place to share my passion for evolutionary biology, which was the subject of my Master’s degree.

NEW | 23rd July – 1st August 2018 (9 nights) | North Cenderawasih Bay & Mapia Island aboard Dewi Nusantara(Manokwari to Manokwari).  This first trip aboard Dewi Nusantara will take us to new ground.  Whilst we will start and end the trip in Cenderawasih Bay, we will take this opportunity to visit Mapia and its surrounding islands 100NM north of the bay, and the equator.  Here the remote and very rarely visited reefs are bustling with life and ripe to be explored.

NEW | 3 – 13th August 2018 (10 nights) | Classic Cenderawasih Bay aboard Dewi Nusantara (Manokwari to Sorong).  Starting in Manokwari, we will sail to the southern reaches of the bay in search of the area’s world renowned whale sharks.  We plan to spend a couple of mornings face to face with the sharks before continuing our search for other amazing fishes found only in the bay.  It is well know for the high numbers of endemics, which you’ll learn all about in my talks!

 

Publications

Sport Diving coverI haven’t only been underwater since my last update; I’ve been busy writing too.  I’ve continued with my regular series in both American and British Sport Diver Magazines, with ‘Get More from your Diving: Critter Hunting’ and ‘Species’ respectively.  I’ve also written the following stand-alone features:

‘Titillating Twilight – The Lure of North Sulawesi’ – Asian Diver

‘A Japanese Spin on the Night Dive – Hot Ke Night’ – Asian Diver

‘Changing Seas: Evolution in the Ocean’ – Scuba Diver AustralAsia

‘Solomon Islands: Reefs at the Edge of the World’ – Scuba Diver – Ocean Planet

‘Shooting for Science’ – Scuba Diver – Ocean Planet

‘Diving Mini Breaks: Australia’ – Sport Diving

‘Diving Mini Breaks: South Pacific’ – Sport Diving

‘Bird’s Head Natural History Notes part 1: In Appreciation of Damsels’ – Bird’s Head Seascape website. A new series about my adventures in the BHS.

Asian Diver coverI’ve also had a couple of cover shots for Asian Diver and Sport Diving magazines as well as having my shot ‘Whip Gobies and Eggs’ judged as a finalist in the ANZANG Nature Photographer of the Year.

Thinking ahead, I will also be speaking at the ADEX dive show in Singapore from 15-17 April 2016, so come along if you can!

 

 

Five Favourite Firsts of 2015

– I am always on the hunt for new and exciting beasties under the sea, so I thought as a final whimsy I would share my top five new finds of 2015.  After 3,000 plus dives there’s still so much to see.  This is why I keep diving and we always donate what we can to help preserve the amazing oceans.

1. Leopard Anemone Shrimp (Izucaris masudai) – Raja Ampat

2. Giant Clam Shrimps (Anchistus demani and Conchodytes tridacnae) – Wakatobi Dive Resort & Raja Ampat

3. Lynne’s Pipefish (Festucalex rufus) – Solomon Islands

Red Sea Longnose Filefish4. Red Sea Longnose Filefish (Oxymonacanthus halli) – Egyptian Red Sea

5. John Dory (Zeus faber) – Izu Peninsula, Japan

Finally, if you’d like to hear what I’m up to on a more regular basis, I suggest you check out my FaceBook page | www.facebook.com/OceanRealmImages

 

 

 

 

Trip Report | Dewi Nusantara, Northern Raja Ampat

Trip Report | Dewi Nusantara, Northern Raja Ampat

I have just returned to Sorong, after another fantastic trip aboard the beautiful Dewi Nusantara around northern Raja Ampat, West Papua, Indonesia.  This was the first of Paul Humann, Ned and Anna DeLoach’s two charters,
so, as you might expect, we have been excitedly looking for all manner of weird and wonderful sea creatures – I’ve been in my element!

Pewter angelfish (Chaetodontoplus dimidiatus)My highlights for this trip included snorkelling with an inquisitive dugong (Dugong dugon) in northern Batanta Island, observing and photographing my first baby Pewter angelfish (Chaetodontoplus dimidiatus) in Aljui Bay in northern Waigeo and seeing a tiny newborn tasselled wobbegong shark (Eucrossorhinus dasypogon) back in Batanata.

It struck me that the words ‘wobbegong’ and ‘dugong’ must have a similar derivation, so I contacted my dear friend, and wobbe-botherer, Jo Stead to clear up the origin of the shark’s name.  Apparently, ‘Wobbegong’ means ‘bearded fish’ in an aboriginal Australian language.  I need to do more research, but I imagine ‘dugong’ must also mean ‘something-fish’.  In any case, the dugong was my first ever in-water experience with these elusive mammals.  I went snorkelling with one of the trip’s guests, Holmes.  Something caught my eye, I looked into the distance and the dugong came towards us.  It circled several meters below us before swimming off after what seemed like hours, but was more likely tens of seconds to a minute.

Newborn tasselled wobbegong shark, Raja AmpatNo less exciting, was the baby wobbegong shark.  It was so small it would have fit in the palm of my hand.  Wobbegongs are live-born, and resemble miniature versions of their parents on birth.  It sat motionless in the centre of a vase sponge, waiting for some prey to happen past it.  The baby pewter angel was also a great sighting.  These fish are found only at scattered locations of northeast Indonesia, and it seems that relatively few images exist of the adults, let alone the juveniles too.

Whilst you may have heard about the impending global coral bleaching event that is being tracked by NOAA scientists, I am happy to report that I have made no observations, as yet, of coral bleaching from Raja Ampat.  Coral bleaching events, such as the massive one in 1998 that killed 16% of the world’s hard corals, are a result of the El Niño phenomenon and are a very real threat to the coral reefs of the world.  Although fine at the moment, the warming waters that cause bleaching are forecast to spread over the coming months, so we will have to wait and see how the world’s reefs fare with this onslaught.  Check out this link to read more about the present global bleaching event forecast – it’s a sobering read.

A lovely striped puffer filefishFunnily enough, Raja Ampat has been facing the opposite effect recently.  We have experienced relentless and unseasonal south winds with unexpectedly cool waters for this time of year.  Usually 28-29˚C, we have had at least 2-3˚C degrees less than this at several of the sites we’ve dived.  Luckily, we planned to stay north for this trip and have enjoyed stunning visibility in the Dampier Strait and been able to dive in some areas of north Waigeo, which are usually inaccessible.  We’re already very excited about the next trip, which promises some exciting diving as ever!

 

If you’d like to see some more of my images from the trip, please check out my gallery HERE.

Originally written for BirdsHeadSeascape.com, and based on this trip, I wrote about my recent rekindled interest in damselfishes for their blog ‘Bird’s Head Natural History Notes: In Appreciation of Damsels‘.  You can read this on the fantastic BHS website by following this link (coming soon) or read below.  The BHS is an online collective, funded in part by Conservation International (one of the beneficiaries from our own ‘Our Beloved Seas’ trip donations – OceanRealmImages.com/Expeditions).  They aim to spread the word about the amazing area that is Raja Ampat and inspire the important region’s conservation.  Check out their website for a mine of information about West Papua and the Bird’s Head Seascape.

 

BIRD’S HEAD SEASCAPE – SCIENCE/CONSERVATION BLOG

Bird’s Head Natural History Notes: In Appreciation of Damsels

By Dr Richard Smith – www.OceanRealmImages.com

Damselfishes are a ubiquitous, but often overlooked, member of the Indo-Pacific reef fish community.  Around two hundred and fifty species, three quarters of the world’s damsels, are known to live in the Indo-West Pacific.  With the world’s highest marine biodiversity, where better to enjoy these fishes first hand than Raja Ampat?

Damselfishes are egg layers, most often laying their clutch on a pre-prepared nest site somewhere on the reef.  When their eggs hatch, the majority of species’ fry will immediately be swept off in the currents to disperse around the ocean.  Whilst the parents of these young fishes will never see the fruits of their reproductive endeavours, others raise young that never seem to leave home: the ‘Gen Y’ of the fish world. Over the past eleven days, I have been exploring the northern islands of Raja Ampat aboard Dewi Nusantara observing this unassuming group of fishes and their array of reproductive strategies.

Ecosystem Engineers

Many of us have had personal experience of a damselfish protecting its eggs.  Sergeant Majors, anemonefishes and golden damsels are amongst a few of the common damsels that will not hesitate to take on us bubble blowers, seemingly unperturbed by our comparatively massive size.  These demersal spawners, lay their eggs directly onto the substrate.  Sergeant Majors nest en masse, with dozens of individuals making a wasteland of a few square metres of the reef, laying their purplish spawn that they enthusiastically protect from marauders.  As such they are a kind of ecosystem engineer, altering the habitat for their own benefit but changing it for others too.

Swimming along a reef in northern Batanta Island, I came across a honeyhead damsel that had also strikingly altered its local environment.  Rather than denuding it to lay its eggs, it had encouraged verdant algal growth within the square metre or so of its territory that it enthusiastically warded me away from.  Like a disgruntled farmer it chased off any other creatures that tried to enter the confines of its little farmyard.  Within the allotment honeyheads farm filamentous algae, which act as their primary food source. Their agricultural proclivities, and the exclusion of other herbivores and corallivores, alter the composition of species within these plots.  By changing patches of the reef, these damsels are altering it for other species too. Their influences having a disproportionately large reach given their size.

Golden damsels on the other hand, usually lay their clutch of bright pink eggs on a whip coral or some other such protuberance coming off the reef.  You’ll often see the diligent parent tending to their clutch.  By aerating and removing infertile or spoiled eggs, they remove a reservoir of infection for others in the clutch.  Like the eggs of many fishes, the initially vivid fresh eggs soon become grey in colour as they mature and the fry develop within.  Just prior to hatching you can even see the reflective eyes of the tiny fish within.

Doting Parents

Spiny chromis adult protecting its fryOne of the more extreme parental investments of a damselfish is found in spiny chromis.  These inconspicuous damsels lay few large eggs, which both parents tend for an extended period until the relatively large fry hatch.  They are rare amongst reef fishes, in that the fry lack a pelagic larval stage and remain close to where they were born their entire life.  Although adults aren’t as protective of their fry as some other damsels, they keep an ever-watchful eye over the brood from hatching until they are quite large in size.  When small the fry are almost transparent, but take on a faint yellow stripe as they grow.  Adult spiny chromis have quite pointed fins and although variable in colour geographically, they are more often than not dark in colour, especially in the West Papua region.  Finally the youngsters darken to become miniature versions of their parents, and even at this late stage remain in a loose school casually overseen by their parents.

Changing Colours

A final quirk of damselfish reproduction, which for me makes them one of the most beautiful reef fish groups, is the diversity of their juvenile forms.  Adult black damsels, for instance, are midnight black in colour whereas their juveniles are almost indistinguishable as the same species.  They are unexpectedly white and bright yellow, with bluey black ventral and anal fins.  The leading theory for the dramatic change in colour or pattern from juvenile to adult in reef fishes is to reduce territorial aggression from adults.  If juveniles appear completely different, the adults are less likely to hound them out of their territory and the two can coexist amicably.

Damselfishes are a group that many divers seem to overlook.  I hope that I’ve convinced you to spare these unassuming fishes a thought on your next visit to the Bird’s Head. The more you learn about these abundant fishes the more fascinating they become, adding both to the diversity of the region and your diving experience.

 

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

 

 

 

Ocean Realm Images FLOW – Newsletter June 2015

Ocean Realm Images FLOW – Newsletter June 2015

 

An update is long overdue but I’ve fallen sadly behind on blogs of my travels, publications and exciting marine life finds of late.  There’s a lot to catch up on here at Ocean Realm Images!

Guests on our Alor charter of Dewi NusantaraCompleted Trips

Since my last blog, I’ve completed several more successful trips as group leader; both alone and with Wendy Brown as ‘Our Beloved Seas’ trips.  The trips have included Tubbataha and Dumaguete in the PhilippinesAlor, Wetar and Wakatobi in Indonesia and most recently Northern Raja Ampat (follow links above to galleries and trip reports).  We saw some amazing marine life living where it shouldn’t (The thinline wobbegong shark (Orectolobus leptolineatus) in Alor and the mimic jawfish (Stalix sp) in Dumaguete) and several firsts for me – including species for which very few sightings have ever occurred (Humann’s fairy wrasse (Cirrhilabrus humanni), new species of flasher wrasse in Alor (Paracheilinus sp.), soft coral pipefish (Siokunichthys breviceps) and harlequin grouper (Cephalopholis polleni)).

Cross's Damselfish juvenileConservation

Wendy and I are very pleased that so far from our three trips, we’ve been able to pass some of the proceeds to conservation efforts specific to the regions we’ve visited.  So far we’ve donated $1500 to help the amazing work of the conservation charities Save Our Seas Foundation and Conservation International.  We both think it’s hugely important that we give something back to preserve the oceans that we love so much.  We hope you agree!

Future Expeditions

There are lots of exciting expeditions in the pipeline too. I have a number of charters coming up this year and all the way through to 2017 (I’ve even started plotting 2018!).  We can still accommodate a few people on trips this year; including the land portion of a trip to Atlantis Dumaguete Resort in the Philippines and in the Solomons too, so do contact me if you’re interested.  Follow the links below for more details or check out my expeditions page here http://oceanrealmimages.com/

Richard giving a talk in London for Dive WorldwideI have also started a new and exciting venture with Dive Worldwide, a UK based diving company for whom I will start leading trips as of February 2016.  I recently gave a talk about our upcoming Philippines trip at London’s Russell Square Hotel.  The talk went very well, and it was apparently the best attendance they’ve had.  It was great to meet some of the folk who have already signed up and those who since have.  Keep your eyes peeled on my social media (Facebook and Twitter) for details of my next talk with them, which is currently in the planning stage.

 

 

Upcoming trips (with spaces):

12-21st September 2015 | Philippines | Land-based stay at Atlantis Dumaguete Resort.

12-22nd December 2015 | Solomon Islands | Live-aboard trip on Bilikiki.

21st February – 2nd March 2016 | Philippines | Trip with Dive Worldwide to Atmosphere Resort, Dumaguete.

18-29th March 2017 | Indonesia | Trip to Triton Bay aboard Dewi Nusantara. Only one cabin remaining.

Richard's Sport Diving cover shot of diver and whale sharkPublications

I’ve been extremely busy writing for various publications around the world.  Since my last update, I have begun writing a regular monthly column for Sport Diver magazine in the US, called ‘Species’, which has so far covered: Crinoids, Goliath Groupers, Caribbean Spiny Lobster, Sea Stars and Whale Sharks.  I also completed my five part series in British Sport Diver magazine ‘Photographing Behaviour’, and have now begun a new series ‘Critter Hunting’.  I’ve also had a series ‘Mini Breaks’ in Sport Diving magazine and a couple of cover shots with them too.  In addition to those regular features, I’ve also had pieces in Wild Travel magazine, Action Asia, Depth Magazine, Aquanaut, Silent World, X-Ray magazine, Diver, Dive!  I’ve been busy to say the least!

Ocean Realm Images…and Films

Finally, if you like moving images, I have recently started shooting HD video with my D800 SLR camera.  The first video that I’ve put together is now up on my YouTube channel ‘Diving The World’s Richest Reefs – Raja Ampat, Indonesia‘.  Check out the link and I hope you enjoy it.

Scientific Publication on Pygmy Seahorse Habitat Specialisation and Population Structure

Scientific Publication on Pygmy Seahorse Habitat Specialisation and Population Structure

My scientific publication on the habitat specialisation and population structure of gorgonian-associated pygmy seahorses has just been published in the journal Marine Ecology Progress Series (Link to the MEPS page):

 

Smith RE, Grutter AS & Tibbetts IR (2012).  Extreme habitat specialisation and population structure of two gorgonian-associated pygmy seahorses.  Marine Ecology Progress Series 444: 195-206

 

The study was conducted on the two species of pygmy seahorse, Bargibant’s (Hippocampus bargibanti) and Denise’s species (H. denise), which require a living gorgonian coral for their survival.  The main findings of my study are below in the paper’s abstract but I’ve also written some of the study’s important findings below.

– Bargibant’s (Hippocampus bargibanti) and Denise’s pygmy seahorses (H. denise) have some of the lowest densities of any unexploited seahorse populations studied thus far.
– Bargibant’s pygmy seahorse is an extreme habitat specialist, being found exclusively in association with a single genus of gorgonian coral, Muricella spp.
– Denise’s pygmy is a relative generalist as it is found in association with at least eight genera of gorgonian corals.
– It is possible to distinguish between male and female pygmy seahorses by examining the area at the base of the abdomen where males have a small slit-like opening to the brood pouch (figure b) and females have a raised, circular urinogential pore (figure a) (see image).

 

Sex discrimination in pygmy seahorses