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Gulf of Guinea Expeditions 

May 22, 2012

The Race: Sixth Gulf of Guinea Expedition Redux

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All of the GG VI participants are home now, and our specimens and materials are safely ensconced in their respective departments at the Academy.  For the first time, we had an official patch for the expedition. The original design of the cobra bobo and giant Begonia was drawn by one my graduate students, Dashiell Harwood. The patch was produced by our friend, Mike Murakami, who played such an important role in the production of the biodiversity coloring books (more about the education project below.) We gave many of these stick-on patches to third grade teachers to hand out as incentives to hard-working students.

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Dr. Iwamoto consuming his favorite, the concon. (A. Stanbridge – GG VI

Soon after Dr. Tomio Iwamoto, our marine ichthyologist and veteran of GGI and GG II returned home to the Academy a few weeks before the last of us, he left for Africa again. And, once again, he is aboard the Norwegian research vessel, the R.V. Nansen, as a senior scientist. I devoted an entire blog to his last trip aboard the Nansen, a couple of years ago.  They are trawling for deep water fish off the coast of Guinea Conakry. I believe the ship will also be exploring the coast of Mauritania in the following weeks. Since he left before we returned we have not been able to discuss his findings during GG VI; but below is a photo of the strange pipefish he and and Dr. Brian Simison seined in northern Sấo Tomé

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Microphis, the only member of its family reported from Sấo Tomé and Príncipe. (B. Simison-GG VI)

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Our botanists had a “a field day,” so to speak.  Recall that Jim Shevock (right) made 682 collections during GG IV, and this time he figured he would just pick up a few things he missed.  Not so. He estimates that among the 647 collections he made in GG VI are between 50 to 100 species of bryophytes he had not seen before, and these include at least 12 genera of liverworts and 12 genera of mosses that are new to the islands.
Miko Nadel (left, above) really has his hands full trying to sort out the lichens; there are 129 previously known species, but Miko made 475 collections, many of which will undoubtedly be new.  He tells me that lichenologists classify lichens by the supporting fungus rather than the symbiotic algae.

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Pico Mesa,  Príncipe ( RCD -  GG III)

In an earlier blog from the islands, I reported that Jim, Miko and our photographer Andrew were the first CAS workersto study the top of Pico do Sấo Tomé. Later on Príncipe, Jim and Miko became the first of us to reach the top of Pico Mesa (above).  Because they had to walk there rather than reaching the base by boat, they were only able to explore the northern most reaches of it; it appears to be a botanist’s paradise, and we will definitely return. Dr. Tom Daniel (GG III and IV) is particularly interested in getting up there as Miko photographed an endemic Impatiens at the top.

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Gabriel, me, Rayna Bell and Joao Pedro Pio at Bom Sucesso (A. Stanbridge – GGVI)

The herpetologists also did well. Rayna and I were assisted by a young Portuguese biologist, Joao Pedro Pio (far right), currently working on the endangered endemic maroon pigeon for workers at the University of Lisbon. He and his co-workers (including Gabriel, left) accompanied Rayna on all of her nocturnal frog hunts.

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Above is Hyperolius molleri, the oceanic treefrog typically inhabiting the lower elevations of both islands. This particular frog is being devoured by a wolf spider and note that it is largely a uniform green in color. In many earlier blogs, I have included images of the Sấo Tomé giant treefrog which is much bigger, has bright orange and black markings and is typically found above 1100 meters.

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Rayna’s sample from between 700 and 900 meters would strongly suggest that the two species are hybridizing at this level.  This is pretty exciting in that, if supported by genetic analysis, it will fit right into her PhD thesis at Cornell University.

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While I failed to find adult specimens of the Príncipe shrew which we know to be endemic and distinct from the Sấo Tomé shrew, we did find the largest “cobra gita” (house snake: Lamprophis sp.) we have ever seen and from a new locality.  This, too, we know to be a distinct species from the Sấo Tomé Lamprophis, but we have thus far been unable to describe it. This is because there are many species of the same genus on the African mainland, and their relationships are poorly understood. So while we know the two island species are distinct from one another, we cannot guarantee that one or the other (or both) does not also occur on the mainland.

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The Príncipe thumbnail-less gecko H. principensis (Weckerphoto – GG III]

While we were on Príncipe I received word that the description our new species of gecko had been formally published, so above meet Hemidactylus principensis.  Like H. greeffi, its nearest relative on Sấo Tomé, it lacks the thumbnail on the first toe, but otherwise, the two are very, very different.

Dr. Brian Simison’s finding that there are no limpets on either Sấo Tomé or Príncipe is intriguing.  Brian informs me that so far as he knows, Sấo Tomé and Príncipe may be the only oceanic islands that lack them.  They are present on the Cape Verde Ids, the Seychelles, etc.

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Dr Brian Simison at Laguna Azul.  (A. Stanbridge – GG VI)

This leads to the possibility that there may be something in the volcanic rock making up these islands that precludes the presence of these mollusks.

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Recall from earlier blogs that all four of the Gulf of Guinea Islands, plus Mt. Cameroon, the Cameroon highlands and even the Jos Plateau of Nigeria all originated from magmatic extrusions up through a 3,000 km-long linear fissure or rift that transects both the marine and continental parts of the African plate known as the Guinea Line; extrusion of magma occurred at various times from over 60 million years ago to the very recent Holocene continental island of Bioko.

The remarkable towers of both Sấo Tomé and Príncipe which appear in these blogs with such frequency are indeed of a rather uncommon, chemically distinct rock known as phonolite, usually associated with geologic hotspots.

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Príncipe, note phonolite towers and mesa on lower left. (A. Stanbridge – GG VI)

One test of the hypothesis that it is something about the rock that is excluding limpets would be to explore the shoreline of Bioko, the youngest of the Gulf of Guinea Ids and the only continental member of the archipelago.  And as luck would have it, our colleague, Rayna Bell will be working on Bioko in a matter of months.  In addition to looking for limpets on Bioko t the presence or absences of limpets along the Gulf of Guinea coast should be documented. If indeed the rock is unsuitable for limpets Brian would predict that limpets would be found on either side of Guinea Line, but not on rocks produced by it.

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(l-r, Roberta Ayres,  Velma Schnoll, me on, Sấo Tomé (A.  Stanbridge – GG VI)

I devoted an entire blog last month to the biodiversity education component of GG VI, and for all of us involved, this was just joyous. We personally delivered 1,840 endemic species coloring books to third graders in 62 classrooms of 17 selected primary schools on both islands. On the big island the schools were in the districts of Sấo Tomé town, Angolares, Trindade and Neves , and on Príncipe  at Santo Antonio, Sundy, Sao Joaquim, Nova Estrella and Praia Abade.

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Porto Real, “my school” on Príncipe  (V. Schnoll – GG VI)

To say they were well received would be a gross understatement.  Again, we thank all who worked on this project (see March 9 blog: Sharing the Wealth; and for those who made GG VI financially possible, see “Partners” below).  At the adult level, we also gave five lectures on the biodiversity of the islands: two in Portugal and three at institutions on the islands themselves.

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Droo doing his thing on Sấo Tomé ( R. Bell – GG VI)

Andrew Stanbridge (above), our photographer on both GG V and GG VI, is a remarkable person in many ways; much more than just a gifted professional artist.  His website is Andrewstanbridge.com

Here are some parting shots:

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PARTNERS

We gratefully acknowledge the support of the G. Lindsay Field Research Fund Hagey Research Venture Fund of the California Academy of Sciences, (GG I, II), the Société de Conservation et Développement (SCD) and Africa’s Eden for logistics, ground transportation and lodging (GG III-V), STePUP of Sao Tome http://www.stepup.st/, Arlindo de Ceita Carvalho, Director General, and Victor Bomfim, and Salvador Sousa Pontes of the Ministry of Environment, Republic of São Tomé and Príncipe for permission to collectexport specimens for study. Special thanks for the generosity of private individuals who have made the GG III-V expeditions possible: George G. Breed, Gerry F. Ohrstrom, Timothy M. Muller, Mrs. W. H. V. Brooke, Mr. and Mrs. Michael Murakami, Hon. Richard C. Livermore, Prof. & Mrs. Evan C. Evans III, Mr. and Mrs. Robert M. Taylor, Velma and Michael Schnoll, and Sheila Farr Nielsen; GG VI supporters include HBD of Bom Bom and the Omali Lodge for logistics and lodging, The Herbst Foundation, The “Blackhawk Gang,” the Docent Council of the California Academy of Sciences in honor of Kathleen Lilienthal, Bernard S. Schulte, Corinne W. Abell, Prof. & Mrs. Evan C. Evans III, John and Judy Sears, John S. Livermore and Elton Welke. Logistics and lodging for GG VI (Omali Lodge and Bom Bom Island) were kindly provided by HBD.


April 8, 2012

The Race: Gulf of Guinea VI, First week

Having completed my lectures at CIBIO near Porto, and in the symposium on Sao Tome and Principe in Lisbon, I hooked up with Drs Tomio Iwamoto, Brian Simison, and James Shevock, Miko Nadel and our outstanding photographer, Andrew Stanbridge in the Lisbon airport whereupon we paid gobs of money in overweight charges to TAP airlines (coloring books). The first six of us arrived at the Omali and have been working in various sites for a week until we were joined by Rayna Bell on the Friday morning flight. Rayna is the Cornell grad student who is looking at some interesting genetic problems with the treefrogs here. Early on I paid visits to Arlindo Carvalho, Director General of the Ministry of the Environment and Victor Bonfim, Director of Conservation to pay our respects and request our authorizations.

All of the photos below are by Andrew Stanbridge.

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The first six of us; lunch at Angolares, southeast Sao Tome

So far, we have found no limpets! Small barnacles, yes; marine mollusks, yes; but no true limpets. Brian is pretty much sampling everything but his specialty critters do not seem to be here. Whether or not there is some chemical feature of the volcanic rock that renders the rocks uninhabitable remains a question. Perhaps Principe will be different.

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Brian Simison (right) searching rocks on Sao Tome west coast.

Jim Shevock has already found two bryophyte families new to the islands, both on the Macambrara road at about 1100 meters. This is Jim’s second trip; in GG IV, he made some 800 collections, so this is stuff we missed.

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Jim reaching for hanging bryophytes on the Rio Abade

Miko Nadel, our grad student from San Francisco State, is conducting what we think is the first lichen survey ever of these oceanic islands- so everything is kind of new.

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Miko with captured lichen; on the road to Sao Nicolau.

Tomio Iwamoto, veteran of GG I and II is working closely with the Department of Fisheries and an NGO called MARAPA to produce a guide primarily for the local fishermen.

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Tomio inspects catches near Agua Ize

Yesterday, after Rayna’s arrival, we went up to inspect the large Olea tree which is our one locality for the unique Hyperolius thomensis. Like last year, we found no adults but there were old egg masses in both tree holes, and definitely tadpoles in one of them. The rains are upon us, and we are hoping that during the next couple of weeks the other smaller green species will appear. We are being assisted by old friends and a new one, a young Portuguese graduate named Joao Pedro Pio who works with Mariana Carvalho on the endemic maroon pigeon. I think Rayna and I, Pedro and a local guy from Nova Moca will go up at night to Lagoa Amelia (nearly 1500 meters) to try to collect Hyperolius molleri.

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Andrew Stanbridge continues to take brilliant pictures. He is much more of an asset to us than just his fabulous shots.

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Andrew with Bode, famed resident of the remote Bombaim. Bode sings the Portuguese national anthem in a truly appalling voice and sells cobra skins. (photo: Brian Simison)

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Me, bargaining for a side-necked turtle (Pelusios castaneus) at Ribeira Afonso

Tuesday, the two botanists and Andrew will go up to the top of the Pico, an area we have never collected. We are being taken there by our friends from Tropic Ventures, Andre, Hugo and Maneh. At the same time, Rayna and I will go out to Rolas Island to look for caecilians. They were collected on the island many years ago and we wish to add them to our genetic map of this unique species.

Here’s the parting shot.

parting-shotImagine thousands of hectares of oil palm between this boy and Cao Grande. It is happening.

PARTNERS

We gratefully acknowledge the support of the G. Lindsay Field Research Fund Hagey Research Venture Fund of the California Academy of Sciences, (GG I, II), the Société de Conservation et Développement (SCD) and Africa’s Eden for logistics, ground transportation and lodging (GG III-V), STePUP of Sao Tome http://www.stepup.st/, Arlindo de Ceita Carvalho, Director General, and Victor Bomfim, and Salvador Sousa Pontes of the Ministry of Environment, Republic of São Tomé and Príncipe for permission to collectexport specimens for study. Special thanks for the generosity of private individuals who have made the GG III-V expeditions possible: George G. Breed, Gerry F. Ohrstrom, Timothy M. Muller, Mrs. W. H. V. Brooke, Mr. and Mrs. Michael Murakami, Hon. Richard C. Livermore, Prof. & Mrs. Evan C. Evans III, Mr. and Mrs. Robert M. Taylor, Velma and Michael Schnoll, and Sheila Farr Nielsen; GG VI supporters include The Herbst Foundation, The “Blackhawk Gang,” the Docent Council of the California Academy of Sciences in honor of Kathleen Lilienthal, Bernard S. Schulte, Corinne W. Abell, John and Judy Sears, John S. Livermore and Elton Welke. Logistics and lodging for GG VI (Omali Lodge and Bom Bom Island) were kindly provided by HBD.

Our expeditions can be supported by tax-free donations to “California Academy of Sciences Gulf of Guinea Fund”.


February 21, 2012

The Race: Gulf of Guinea VI, Part I (the Science)

Things have been very busy here at the Academy of Sciences, and this is one of my tardier blogs! However, part of the hustle and bustle has been in planning our next expedition, Gulf of Guinea VI.

The first good news is that our new species of gecko from Príncipe is about to be formally published in the African Journal of Herpetology, possibly as soon as April. It is bad luck to give you its name before it is published, but here is what it looks like, and we are adding yet another endemic species to our wonderful islands!

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Our new gecko near Bom Bom, Principe.  Weckerphoto- GG IV

As readers know, our expeditions have largely been privately funded since GG III, and the friends who have helped us are always celebrated in the PARTNERS section below.  However, I am going to take this early opportunity to thank the folks who are making the upcoming expedition financially possible: The Herbst Foundation, The “Blackhawk Gang,” the Docent Council of the California Academy of Sciences in honor of Kathleen Lilienthal, Prof. & Mrs. Evan C. Evans III, Bernard S. Schulte, John S. Livermore, John and Judy Sears and Elton Welke.

Here are the scientist participants in the upcoming GG VI which will run from 30 March until 5 May.

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Dr. Tomio Iwamoto on Sao Tome.  D Lin phot- GGI

Dr. Tomio Iwamoto is Curator Emeritus of our Ichthyology Department, and my good friend and flyfishing buddy.  He is a veteran of GG I and GG II and has already published two scientific papers as a result of these expeditions. He has also worked with São Tomé and Príncipe fisheries people in deepwater trawling around the islands (see Shipboard Discoveries….June 2010 blog).  During GG VI he wants to visit as many local fishing villages as he can on both islands to see what the most commonly caught fishes are.  His goal is to produce a popular guide for the fishermen themselves! This will not be a scientific publication.

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A Longfin crevalle jack described to science only 5 years ago. Sao Tome.  A. Stanbridge phot- GG V

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Dr. Brian Simison; limpet photo by  T. Laupstad]

Dr. Brian Simison is a world authority on small monovalved molluscs known as limpets, commonly found firmly attached to rocks in the coastal littoral zones.  So far as we know, this group has never before been sampled in São Tomé and Príncipe, and our expectations for new discoveries are high.

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Crocidura tomensis, the Sao Tome shrew. Phot by Ricardo Lima, 2010

Brian is alsoDirector of the Academy’s  Center for Comparative Genomics which is where all our genetic and molecular work is done.  He became involved in our molecular analyses of the true status of the endemic São Tomé shrew (see Unique shrew…. August 2010 blog).  Working with Eden Maloney, he discovered that the shrew on Príncipe, long thought to be a mainland species, may indeed also be an endemic to that island.  While we collected DNA of this second shrew during GG II, we collected no adults.  Assuming we receive permission from the Ministry, Brian and I will also try to secure a couple of adult Príncipe shrews. If this is indeed a unique species, we will need to be able do describe its anatomy formally.

Two graduate students will be joining us.  The first is Rayna Bell who is doing her PhD on African tree frogs at Cornell University.

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Oceanic tree frog, Hyperolius thomensis (phot RCD- GG I); Rayna Bell

Rayna will be looking at a potential hybrid zone between the oceanic tree frog (above, Hyperolius molleri) and the flambouyant São Tomé giant tree frog, H. thomensis of higher elevations, which I have featured in many of these blogs.  There is something curious going on with the genetics of these species and one of Rayna’s projects will be to look at both populations from the molecular perspective.

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Miko Nadel and lichens (from web)

Our other graduate student is Miko Nadel, who is doing his MSc in botany at San Francisco State University under the guidance of our favorite mycologist, Dr. Dennis Desjardin, describer of the now infamous Phallus drewesi of São Tomé.  Recall that Drs. Desjardin (GG II & III) and Perry (GG III) learned that over 33% of the mushrooms of São Tomé and Príncipe are new to science.  Miko informs me that there have been only a couple of scientific papers ever written on the lichens of the islands, and that was back in the 1880’s.  So it is time for a more modern and thorough look at this flora.

Finally, we round the scientist group out with the irrepressible  James Shevock, the Academy’s bryophyte (mosses and their allies) expert.

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Jim Shevock with moss at the Omali.  RCD phot-GG IV

The results of Jim’s efforts during GG IV are summarized in the image below.  The largest uptick of new species for the islands is expected in the third paper, which we hope will be published this year.

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Compilation and photo by RCD, GG IV (* this paper has since been published)

As in GG V, the new expedition will be accompanied by the world’s largest photographer, Andrew Stanbridge.  His images from GG V are magnificent, and he is a most excellent and willing field companion. His work can be viewed on the web at www.andrewstanbridge.com


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RCD and photographer Andrew Stanbridge. V. Schnoll phot – GG V

There will be two additional members of GG VI, both veterans of earlier expeditions,  Ms Velma Schnoll and Ms Roberta Ayres, but I will reintroduce  them in more detail in the second part of this blog which will be on our concurrent biodiversity education activities.

The parting shot:

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The Jockey’s bonnet, Principe. Photo by Eddie Herbst – 2011

[Herbst]

PARTNERS

We gratefully acknowledge the support of the G. Lindsay Field Research Fund Hagey Research Venture Fund of the California Academy of Sciences, (GG I, II), the Société de Conservation et Développement (SCD) and Africa’s Eden for logistics, ground transportation and lodging (GG III-V), STePUP of Sao Tome http://www.stepup.st/, Arlindo de Ceita Carvalho, Director General, and Victor Bomfim,  and Salvador Sousa Pontes of the Ministry of Environment, Republic of São Tomé and Príncipe for permission to export specimens for study.  Special thanks for the generosity of private individuals who have made the GG III-V  expeditions possible: George G. Breed, Gerry F. Ohrstrom, Timothy M. Muller, Mrs. W. H. V. Brooke, Mr. and Mrs. Michael Murakami, Hon. Richard C. Livermore, Prof. & Mrs. Evan C. Evans III, Mr. and Mrs. Robert M. Taylor, Velma and Michael Schnoll, Sheila Farr Nielsen, Corinne W. Abel and Mr. and Mrs. John Sears, Bernard Schulte, and John S. Livemore.   Our expeditions can be supported by tax-free donations to “California Academy of Sciences Gulf of Guinea Fund”.


October 19, 2011

The Race: New Species, New People and Intriguing Biogeography

Lots of news this time. First, graduate students of the University of California, Santa Cruz and California State University, Monterey Bay teamed up to do a most excellent on-line presentation of our work in the Gulf of Guinea Islands, called Documenting Eden; it includes a slide show and can be found here: http://sciencenotes.ucsc.edu/2011/pages/eden/eden.html
On the biodiversity education front led by Velma Schnoll, we are working on several projects including a coloring book of endemic species, a lesson plan to support our poster project of GG V and possibly an animated cartoon featuring the fabulous yellow caecilian, cobra bobo, as “spokescreature” for the unique species on the  islands.
Some great news is that the Academy has hired three new Curators in Microbiology, Herpetology and Ichthyology.

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Dr. Luiz Rocha, CAS Ichthyology Section.  RCD phot.

Dr. Rocha (above) is a marine ichthyologist and brilliant underwater photographer who has already worked in São Tomé and Príncipe. He was a member of a National Geographic-sponsored marine expedition in 2006 which occurred shortly after our CAS GG II expedition concluded.  The results were published in the journal Zootaxa a year later and included many of the fishes already collected on our first two expeditions by Dr. Tomio Iwamoto and others of us.

I walked into Luiz’ lab a couple of weeks ago just to talk, and found he was just finishing up the description of a new species of parrotfish from Säo Tomé, based on three specimens we collected  on earlier CAS expeditions!

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Sparisoma sp. nov., new São Tomé parrotfish. L. Rocha phot

The holotype specimen (the single “name bearer”) was collected by Dr. Tomio Iwamoto in 2006 (GG II) by hook and line from Ned Seligman’s pier on Praia Francesa.   Readers of this blog will remember that Ned is the head of an island NGO called STeP UP through which we have worked since the beginning in 2000; he is also a life-long friend of mine.

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Chez Ned (l) and the author (r),  Praia Francesa  T. Daniel phot. GG IV

The additional specimens (paratypes) include another collected directly from a beach seine by Tomio and I in 2001(GG I), and one purchased from the town fish market by Dr. John McCosker and David Catania in 2009 (GG IIIB).   It is very exciting to have a bright new colleague here at the Academy who is interested in the Gulf of Guinea; the manuscript is in review and as always, we will send the published article to the islands.

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Jim Shevock, Laguna Azul.  RCD phot GG IV

Meanwhile, our tireless moss guru, Jim Shevock, and colleagues from Dresden and Hungary have published another paper on the GG IV bryophyte collections; we have already sent the paper to the islands.  As a result of Jim’s GG IV work, the authors report 18 species of liverworts and hornworts  (moss relatives) as new for the Republic of São Tomé and Príncipe overall.  With respect to the two islands, 13 new species records have been found new to Príncipe and 16 new for São Tomé.  None of these species is new to science, but the country list for liverworts and hornworts is now 147 species, a much greater diversity than was known.

My lab has been quite active all summer.  Eden Maloney returned from UCLA to further refine the genetic component of her work on the endemic São Tomé shrew, Crocidura thomensis; this research includes the ecological work by our colleague Ricardo Lima, a doctoral student at  Lancaster University and genetic work by Dr. Brian Simison, Director of our Center for Comparative Genomics.

Much of our recent focus in the lab has been on the endemic, Greeff’s  giant gecko, Hemidactylus greeffi,  described from São Tomé by the Portuguese biologist Bocage in 1886.

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Greeff’s giant gecko (Hemidactylus greeffi), road culvert, Praia Mutamba. D. Lin phot. GG I

This species is unique among the 90+ members of the genus Hemidactylus,  in that it lacks the claw and the actual terminal bone (phalanx) of the thumb.

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Bom Bom, Principe Weckerphoto -  GG IV

Evolutionary loss of the first claw is known from a species in Brazil, H. brasileanus but until now, absence of the underlying terminal phalanx has been thought to be unique to Greeff’s giant gecko.

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Hemidactylus brasileanus phot: animaldiversity, U. Michigan

H. greeffi was thought to inhabit both São Tomé and Príncipe islands but in 2005, our colleague, José Jesus of the University of Madeira and his co-workers compared the genetics of samples from both islands and found significant differences in mitochondrial DNA sequence between them.  However, they did not find any differences in the nuclear genes they examined and thus deferred describing the Príncipe individuals as new.

In June, I tasked my Summer Systematics Intern, Elizabeth Miller of UC San Diego, with doing a detailed anatomical examination of our collections of the geckos from both islands, along with a molecular study of the two populations using the data kindly sent to us from Dr. Jesus but also employing new, faster-evolving nuclear genes.

Long before the genetic analysis was completed, Elizabeth found obvious and consistent morphological differences between the two populations.   In fact, these differences are so striking that I think if anyone had ever done careful comparison of the bodies of the two sets of geckos, the Príncipe population would have been described as a separate species long ago, DNA evidence notwithstanding.

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left, Sao Tome, D. Lin phot- GGI;  right, Principe, Weckerphoto GG III

Among the many character differences she found was in iris color!  H. greeffi of São Tomé has beautiful light, moss-green eyes, while in the Príncipe population, the eyes range from gold to light copper.  This would seem to be an obvious, readily recognizable difference, but it must be remembered that except for Dr. Jesus and his colleagues, all previous scientists who have studied these geckos have been dealing with preserved specimens, in which eye color is invariably lost—in fact much body pigmentation is lost in museum preservatives .

Subsequent DNA sequence data generated by Elizabeth in our Center for Comparative Genomics confirmed that José Jesus and his colleagues were correct; the Príncipe populations do indeed represent a separate, undescribed species.  At the same time, however, they share with H. greeffi of São Tomé the absence of the terminal phalanx of the thumb; this strongly suggests that H. greeffi and H. sp. nov. are each other’s closest relatives (but more on this below).

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Miller (back left) presenting our results to the Summer Systematics Institute, August 2011 RCD phot

Currently Elizabeth and I, along with Anna Sellas of our CCG molecular lab are completing a formal description of the new gecko from Príncipe.  The two gecko species, along with their purported nearest relatives present quite an interesting biogeographical question, now being addressed by my graduate student, Dashiell Harwood.  At first glance, our molecular results suggest that the ancestor of both H. greeffi and the new Príncipe species colonized São Tomé first, then later made it across to Príncipe but we have a number of reasons for doubting this scenario.   Part of Harwood’s project will be to employ Elizabeth’s data plus additional genes and deeper analysis in order to answer this initial question.  But if we can obtain appropriate samples, there is a much broader gecko issue we can study.

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cladogram from Bauer et al. (2010) Mol. Phylo. Ev. 57

Above is a small subset of a much larger cladogram of Hemidactylus species done by our colleague Dr. Aaron Bauer of Villanova University and his co-workers.  The highlighted box indicates H. greeffi and its closest known relatives, H. longicephalus of the African mainland (also São Tomé) and H. brasileanus of South America.  The species examined in Bauer’s study did not include samples of our new gecko from Príncipe Island.

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African-Atlantic partial distribution.

The image above is a visual perspective of the rough distributions of four species of Hemidactylus, including Príncipe.  If the cladogram is a true reflection of the relationships of three of the four species here, and if the Príncipe gecko is indeed, H. greeffi’s closest relative and fits in as we surmise, then the common ancestor of all four species must have crossed the Atlantic, from the African continent to northern South America.   This is not a new idea and was proposed by Carranza and Arnold in 2006, who stated that during the last 15 million years, African lineages have crossed the Atlantic by random (natural) dispersal at least twice.  The likelihood of this long-range dispersal is strengthened by a look at the dominant Atlantic currents.  Readers of the blog will recognize the South Equatorial Current as the same one we invoke as providing a “freshwater pathway” for rafting from the Congo and Niger Rivers on the mainland, straight through the Gulf of Guinea archipelago (see Oct and Nov, 2008 blogs and Measey, et. al (2007) Journal of Biogeography 34.)

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Major Atlantic Ocean Currents

In the Carranza and Arnold paper, H. longicephalus and three additional Brazilian species were employed, as was “H. greeffi”; however, the tissues we sent the authors were from Príncipe, before we knew the two island populations were distinct.  So Harwood’s graduate work should shed some light not only on the relationships between these geckos, but their geographic origins and history.

Here’s the Parting shot:

sunset-rwSunset on Bom Bom Island, R. Wenk phot.  GG IV

PARTNERS

We gratefully acknowledge the support of the G. Lindsay Field Research Fund Hagey Research Venture Fund of the California Academy of Sciences, (GG I, II), the Société de Conservation et Développement (SCD) and Africa’s Eden for logistics, ground transportation and lodging (GG III-V), STePUP of Sao Tome http://www.stepup.st/, Arlindo de Ceita Carvalho, Director General, and Victor Bomfim, Salvador Sousa Pontes and Danilo Barbero of the Ministry of Environment, Republic of São Tomé and Príncipe for permission to export specimens for study, the support of Bastien Loloum of Zuntabawe  and Faustino Oliviera, Curator of the Herbarium at Bom Sucesso. Special thanks for the generosity of private individuals who have made the last three expeditions possible: George G. Breed, Gerry F. Ohrstrom, Timothy M. Muller, Mrs. W. H. V. Brooke, Mr. and Mrs. Michael Murakami, Hon. Richard C. Livermore, Prof. & Mrs. Evan C. Evans III, Mr. and Mrs. Robert M. Taylor, Velma and Michael Schnoll and Sheila Farr Nielsen. Our expeditions can be supported by tax-free donations to “California Academy of Sciences Gulf of Guinea Fund”.



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