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Gulf of Guinea Expeditions 

March 5, 2014

The Race: The Amphibians of Sâo Tomé and Príncipe, and the Eighth Expedition

The Biodiversity Education team has been hard at work on our product for GG VIII, of April, 2014.  The 2000 students we have been visiting since the 3rd grade are now in the 5th grade and will be moving on next year, so this is our last visit with them.  We have produced a slightly more technical biodiversity booklet (livreto) for each of them. This cohort represents slightly more than 35% of the island studentsin their age group.

bio reader small

NOSSAS PLANTAS E ANIMAIS ESPECIAIS.

 

2014 BioTeam

The Bio-education team in my Lab: Roberta Ayers (senior educator, and translation – on Skype), Velma Schnoll (Project Manager), Lindzy Bivings (education advisor),Jim Boyer (art work and layout), Tom Daniel (science text).Absent: Mike Murakami (graphics), me..

Just recently a great new book was published called The Monkey’s Journey, by Alan de Queiroz.  An entire chapter (6) is based on our hypothesis as to how amphibians and many of the other unexpected, endemic animals originally crossed over to the islands from the mainland.

alans book

One of us has made an exciting discovery recently (see below) which prompts me to reacquaint readers with the amazing amphibian fauna of Sâo Tomé and Príncipe.  As readers already know, there should not be any amphibians on these islands at all;  they are true oceanic islands which have never been attached to the African mainland, and amphibians have no tolerance for saltwater. There are no native amphibians on the Galapagos or the Hawaiian Islands for this reason. Yet, there are seven species on our islands, possibly eight – all unique and found nowhere else in the world!  The most unlikely of these is the famous “Cobra bobo” of Sâo Tomé.

Q hand shot

Cobra Bobo in the hands of Quintino Quade of Sao Tome. D. Lin phot – GG I

live bearing and collage

 Upper left, unknown phot, upper right, RCD GGI, lower, R. A. Nussbaum

The cobra bobo (Schistometopum thomense) is a caecilian, part of a group of amphibians only distantly related to frogs and salamanders. They are found almost exclusively in the Old and New World Tropics. About 25% of the 200 species lay eggs, the rest, including our cobra bobo give birth to living young (see above).

unique chars

Although they look very much like earthworms, caecilians have backbones, teeth and a vertebral columns. (above lef-UCL photot). Most are burrowers although some are aquatic, but all caecilians lack legs, tails and have reduced eyes, and they are the only amphibians that have sensory tentacles located on each side of the head, between the nostril and the eye (above right – different species-J. Measey phot.).  These are protruded to sense prey items and the environment.

The cobra bobo is widespread under moist leaf litter, old banana stems, etc from sea level to as high as 1400m, at Lagoa Amelia. Although they are totally harmless, they are widely feared by the islanders, which is the reason we use a cobra bobo cartoon for our expedition logo (see earlier posts). We are attempting to demystify it. One of the most interesting things about this endemic species is the distribution of its closest relative.

schisto dist.

Note that several thousand km separate the two known species; the red ? indicates a single old specimen in Brussels from the Ituri region of Zaire that might also be a member of the same genus.

A frog unique to Sâo Tomé is Newton’s rocket frog, Ptychadena newtoni. There are over 50 species recognized on the African mainland, but this endemic is by far the largest of the genus, with females attaining lengths of over 60mm. This qualifies Newton’s rocket frog as a true “island giant.”

adult Ptychs

Newton’s rocket frog. above phot RCD- GGI, below A. Stanbridge,-GGVI

Early records suggested it is a frog of streams and rivers in the northern lower elevations, but we have found its larvae as high as Java, at 600m, and in recent years, Hugualay Maya of ABS has discovered the species in river drainages farther south down the west coast. (pink markers).

P newtonii localities

Known localities for Newton’s rocket frog. RCD construct

Frog larvae (or tadpoles as they are often known in English) are used in identification of species by scientists, as well as the study of adults and are formally described.

newtoniX

Ptychadena newtoni.  above, whole larva; below are mouthparts] drawings -Dylan Kargas.

An extremely interesting fact about Newton’s rocket frog is the location of its closest relatives.  Like the cobra bobo, the species of Ptychadena genetically closest to our island frog are eastern species, not Central or West African.

ptcy dsit

This study included 108 rocket frog samples from all over sub-Saharan Africa, including the Nile drainage, Madagascar and the Seychelles.

Another endemic island giant is Príncipe’s giant treefrog, Leptopelis palmatus. In fact, the first specimen ever collected and described nearly 150 years ago was a female measuring 110mm from snout to between the legs. This is the largest ever recorded for the genus.  The largest specimen we have collected was a 108mm female, during GG I near Sundi.

large female

 Sundi female of 108mm. D. Lin phot-GG I

big lepto and male

Left:  same female, R Stoelting phot. GG I; right: Pico Papagaio male, just after calling.  Weckerphoto GG III

There are a number of strange things about this species; the females are usually always dark to dull green, while the males come in a great range of color patterns, some quite bright (polychromatic- see below). Moreover, the largest males are usually less than half the size of the females (above and below).  While we were the first to record its call, this is the one species on both islands for which we have no data for eggs or larvae. Most large females have been found in the lowlands of Príncipe, while males seem to be common up to 700m on the Pico.

polychromatism

Three males and a juvenile Principe giant tree frog.  J. Ledford phot- GG I

lepto nearest

Distribution of the Príncipe giant tree frog and its closest mainland relative, L. macrotis.  This may suggest that the ancestor of both rafted from the Niger River delta into the Gulf of Guinea.

Both islands have small species of puddle frog, Phrynobatrachus, that are widely distributed on both islands in leaf litter, and breed in temporary puddles of water. Both island forms were thought to be the same species (they are tiny and remarkably similar to the untrained eye) until we discovered that they were genetically quite distinct species with physical differences.

dispar principe

The Príncipe puddle frog, Phrynobatrachus dispar, can be found in wet areas from sea level to the top of Pico do Príncipe. While we have its larvae and eggs, we have not yet described them. D. Lin phots-GG II.

leveleve comp

The Sao Tome puddle frog, Phrynobatrachus leveleve  is very similar in appearance to the Príncipe species but there are great genetic differences and physical differences as well.  Like its relative on Príncipe, it is broadly distributed in wet areas from sea level to very high elevations. RCD phots, GG VI.

Its larval characteristics can be seen below.

leveleveX

Drawings: Dylan Kargas

Like the other amphibians, the distribution of the nearest relatives of our two island puddle frogs is intriguing.

phryno phylo

According to a recent study, Príncipe’s puddle frog, P. dispar is most closely related to a population in the Caprivi Strip of Namibia, and together their nearest relative is P. leveleve of Sâo Tomé. The interesting thing to notice is that all of the other members of this lineage, called a clade and defined by the purple box, are East African species.  This is reminiscent of the rocket frog and cobra bobo distributions.

Returning to island giants, we have the Sâo Tomé giant treefrog, Hyperolius thomensis. There are well over 200 species of this genus known from the African mainland, and females of this Sâo Tomé endemic are by far the largest at just under 50mm.

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D. Lin phot- GG I

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D.Lin phot. GG – I

 thom amplexus

Breeding pair of Sao Tome giant treefrog. D. Lin phot, GG II

This large flamboyant tree frog appears to largely be a tree canopy dweller.  We have discovered that eggs are laid in water-filled holes in trees (phytotelmata). They can be heard calling from treetops but are extremely difficult to locate; in fact all of our specimens have come from a single locality at around 1100m; we monitor this locality every year and keep its exact location a secret.  We have described the larval characteristics, below.

Hyperolius thomensis tads

 Drawings by Dylan Kargas

Our last endemic species is closely related to the Sâo Tomé giant tree frog, although it is much smaller and not so brightly colored: Hyperolius molleri, the oceanic tree frog. Since our work began, it is the only remaining amphibian that has been thought to inhabit both Sâo Tomé and Príncipe.  In fact, years ago an early intern of mine, Katie Marshall, compared the two populations using mitochondrial genes and found no significant differences between them; they are certainly extremely similar morphologically ( see below).

2 molleris

Above, Weckerphoto GG III; below, RCD phot GG I

Recent work by Rayna Bell, our Cornell colleague (GG VI, VII) included a reanalysis of the two populations with more advanced technology, and indications are that the two populations may be quite distinct genetically. If this turns out to be the case, the Príncipe population will require much closer morphological examination and redescription, bringing the total number of endemic amphibians on our islands to eight!

While this small green tree frog appears to be a lower elevation dweller on Príncipe, on Sâo Tomé it reaches at least 1400m and can be heard calling at Lagoa Amelia. Like most other members of the genus, eggs are laid on leaves above water, the developing tadpoles ultimately wiggling out of the jelly mass and falling into the water for further development.  We have studied the larvae of the big island form (the original Hyperolius molleri- the species was described based on a specimen from that island) and the characteristics are below.

Hyperolius molleri ST

Drawings by Dylan Kargas

The team leaves for the islands in early April; our mission for GG VIII will largely be on biodiversity education as I mentioned in the beginning, but we will continue to post on our progress while there.

Until then, here is the parting shot:

b-b kingfisher Bronkhorst

The brilliant Blue-breasted kingfisher of Principe Island.  Photo by Michael “Bobby” Bronkhorst, 2014

PARTNERS
We are most grateful to Arlindo de Ceita Carvalho, Director General, Victor Bomfim, and Salvador Sousa Pontes of the Ministry of Environment, Republic of São Tomé and Príncipe for their continuing authorization to collect and export specimens for study, and to Ned Seligman, Roberta dos Santos and Quintino Quade of STePUP of Sao Tomehttp://www.stepup.st/, our “home away from home”. We gratefully acknowledge the support of the G. Lindsay Field Research Fund, Hagey Research Venture Fund of the California Academy of Sciences for largely funding our initial two expeditions (GG I, II). The Société de Conservation et Développement (SCD) and Africa’s Eden provided logistics, ground transportation and lodging (GG III-V), and special thanks for the generosity of private individuals who 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 Bom Bom Island 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. Abel, Prof. & Mrs. Evan C. Evans III, Mr. and Mrs. John Sears, John S. Livermore and Elton Welke. GG VII was funded by a very generous grant from The William K. Bowes Jr. Foundation, and substantial donations from Mrs. W.H.V.“D.A.” Brooke, Thomas B. Livermore, Rod C. M. Hall, Timothy M. Muller, Prof. and Mrs. Evan C. Evans, Mr. and Mrs. John L. Sullivan Jr., Clarence G. Donahue, Mr. and Mrs. John Sears, and a heartening number of “Coolies”, “Blackhawk Gang” returnees and members of the Academy Docent Council. Once again we are deeply grateful for the continued support of the Omali Lodge (São Tomé) and Bom Bom Island (Príncipe) for both logistics and lodging and especially for sponsoring part our education efforts for GG VII and GG VIII. Substantial support has already come in for our next expeditions from donors in memory of the late Michael Alan Schnoll, beloved husband of our island biodiversity education Project Manager, Velma.
Our expeditions can be supported by tax-deductable donations to “California Academy of Sciences Gulf of Guinea Fund”


August 22, 2012

The Race: Why We Collect Specimens.

Summer has been extremely busy.   Our irrepressible bryologist, Jim Shevock, comes into my lab almost weekly with new moss discoveries from GG VI.  He says a new paper on Fissidens (the largest moss genus on Sâo Tomé and Príncipe) is almost finished and will be submitted for publication as soon as he and his colleagues (from the US, the Netherlands and Lisbon) complete a key to identification of the species. Recall that Jim nearly doubled the number of collections he made during GG IV… He thought he had seen everything! The mesa on Príncipe will be a primary target for our botanists on GG VII, next year (see below).

Phrynobatrachus leveleve – RCD phot, GG VI

A nice surprise from GG VI was that we finally got some nice, un-posed  photographs of the Sâo Tomé puddle frog, Phrynobatrachus leveleve. Readers may recall that we described this new endemic species back in 2007 following GG II (leve leve means “take it easy” in the local language).  Obviously the way to get good shots of these critters is at night!

Ptychadena newtoni.  A. Stanbridge phot – GG VI

Another good find on a different night was Newton’s rocket frog (Ptychadena newtoni) at a new locality, Caxueira.

The creek at Caxueira.    A. Stanbridge phot. – GG VI

In earlier days I was concerned that this species, endemic to Sâo Tomé, was on the wane due to human development, but it appears to be more widely distributed than we thought (see also Feb 2011 blog). Caxueira is not far from the city center.

Why do we collect plant and animal specimens? Why do we bring them home euthanized and preserved (or in the case of plants, pressed and dried), and why do we organize and store them for posterity?  The easy answer is that we need to find out what they are, to identify them and describe them so we can communicate about them.  We certainly cannot conserve or preserve or even talk about species if we do not know they exist. This is particularly important in the tropics where so many different species have evolved, and especially in areas like Sâo Tomé and Príncipe that have never been fully explored by biologists.  An added note is that for a biologist to know that a species is new and undescribed, he has to know all the related species that it isn’t and then demonstrate it!

It is a fact that a lot of things in the tropics that look alike are not at all related; conversely, some critters that look radically different are, in fact, just variants of the same species.

The botanists of course confront similar questions. Below are two species of the genus Impatiens.

(l) T. Daniel phot – GG IV; (r) M. Nadel phot – GG VI

Both species are high elevation forms described a long time ago: I. manteroana is thought to be endemic to Príncipe, while I. thomensis is known only from Sâo Tomé. But are they really different species? And if so, are they each other’s closest relatives?  We do not yet have material of the former, but this is a question we can answer next year through DNA analysis. The specimen on the right was photographed high on the Príncipe mesa, which is one of the reasons it is a target area for next year.

Below is an island example of two species that look very much alike but are definitely not the same:

D. Lin phots: GG I, GG II]

These are photographs of small leaf-litter skinks of the genus Afroablepharus. The specimen above was collected on Sâo Tomé during GG I and the one below came from Príncipe (GG II).  While they look identical, they are actually two different species as shown by colleagues of ours who were working on the molecular level: extracting DNA from small bits of tissue (probably tail tips) the two species were shown to be genetically quite different.  The one from Príncipe was described over 160 years ago (A. africanus), while the one above, from Sâo Tomé, remains unnamed. This is most frustrating as even though we know they are separate species, we cannot describe the new species yet because the Sâo Tomé animals from which the DNA was analyzed were not collected.  It is a complicated situation that both groups of workers together are trying to resolve at this time.

Another example can be found in the island geckos about which I have written before.

From public presentation by E Miller. CAS Big Kahuna phot (same specimens from above and below).

For over one hundred years, the geckos from both islands that lack thumb nails were considered to be the same species, Hemidactylus greeffi, originally described from Sao Tome.  Our same colleagues noted that the two were genetically different but again failed to take whole samples and so could not describe the Príncipe species as new.  It was not until we closely examined specimens in our Academy collections from both islands that we found many morphological differences between the two, which strongly supported the genetic evidence of our colleagues.  The animal on the right is now  known as Hemidactylus principensis, yet another island endemic. As luck would have it, the paper was published while we were on Principe!

The smaller specimen on the right in both views is also what is known as the holotype; i.e., it is the single animal that is described in minute detail that becomes the “name bearer”.  All geckos collected from the islands and identified as H. principensis will be based on the description of this particular specimen; holotypes are the most important specimens in any collection.

In our collection, which is probably the fifth largest in the world, all holotypes are housed separately and identified by a blue ribbon.

Part of Herpetology collections rooms; holotypes above right, paratypes below right. RCD phots.

Another question often asked of museum scientists is “why do you have to collect so many?”  The answer is that species vary; no two members of the same vertebrate species are identical.  This is why we include additional specimens in a species description.  While the holotype or “name bearer” is usually a single animal in a standard description, other members of the same purported species, hopefully from the same place, are also described in some detail in order to account for individual variation.  These are usually designated as paratypes; in the Academy collections, they are always designated by red ribbons [above] and are the second-most important.

Yet another frequently asked question is, “do you have to kill the specimens?”  The answer lies in the fact that not all characters (similarities and differences) are observable from the outside.  With animal groups like frogs, one has to look deeper, and this is impossible with living specimens. Below is a collage of some of the sorts of characters I had to examine in determining the relationships between members of African tree frogs of the family Hyperoliidae— found in Africa, the Seychelles and Madagascar.

All RCD phots.

Notice that the x-ray in the lower right hand corner revealed to us that the two geckos mentioned above not only lack thumb nails, they lack the entire terminal bone of the thumb! (the new species, Hemidactylus principensis, is on the left). So far as we know, they are the only two members of the genus Hemidactylus, (90+ species) that exhibit this characteristic.  This might suggest they are each other’s closest relatives, but we are in the process of determining that by further DNA analysis that includes other closely related species.

During GG VI we did another kind of collecting:

Rayna Bell, Cornell University. A. Stanbridge phot – GG VI

Notice that in her left hand, Rayna Bell is holding an adult Sao Tome giant treefrog (Hyperolius thomensis), while in her right she has a cotton swab.  She swabbed the skin of each frog she collected a number of times in a number of places in order to detect the presence of chytrid fungus. The swab will also detect the actual infection load if the fungus is present.  This is the first attempt at detecting the fungus on the islands of Sâo Tomé and Príncipe, and we do not yet have results. It is certainly present in other areas of Africa. Batrachochytridium dendrobatidis (Bd for short) is a fungus that has been implicated in the mass die-off of populations of frogs in many parts of the world.  Frog skin is a living membrane through which gasses and water can freely pass; while the mechanism is not well-known, the fungus seems to totally disrupt these functions causing the demise of the infected frog.

Cross section of Bd infected frog skin.  (A) are sporangia with zoospores visible. (B) tube through which zoospores are released to the environment. Phot courtesy of A. Pessier, U. Illinois

Another real value to collections is the fact that past history can be discovered through our specimens. It turns out that Bd can also be detected by swabbing alcohol preserved specimens regardless of age, although the resulting data are not quite so informative as samples from living material.  Below is Dr. Dave Blackburn’s “chytrid crew” (mostly undergrad and graduate students) swabbing specimens collected from the Impenetrable Forest of Uganda many years ago.  Dave is our new curator in herpetology and a real expert on Bd.

Dave Blackburn’s “chytrid crew”.  D. Blackburn phot.

Every trip to these small amazing islands yields new discoveries. We are planning our next expedition for 2013 and excited at the prospect of the new stuff we will find.

Here’s the parting shot.

Autonomy Day in Principe, 2012 A. Stanbridge phot, GG VI

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 collect and export specimens for study. Special thanks for the generosity of private individuals who 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.

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


April 22, 2011

The Race: The Sharing Begins

This is our seventh day, and we have been to all the schools, ministries, health centers and public places we can find, giving our biodiversity posters to head masters, principals, ministers. etc.. We started at the southern end of Sao Tome on one side, the town of Santa Catarina and worked north; then Porto Alegre on the east coast, working toward the city. This morning we delivered posters to a number of the bigger town schools but then spent the afternoon hunting spiders in the garden of Henrique da Costa, former Minister of Agriculture and a dear friend and wise counselor. As to our main mission, how have our posters been received? I thought I would just post a number of images of our poster adventures, and you can decide for yourself!

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And of course we had to jump back in the bush:

The Parting Shot:

partingshit-1

PARTNERS
We gratefully acknowledge the support of the G. Lindsay Field Research Fund (GG I), Hagey Research Venture Fund (GG II) of the California Academy of Sciences, 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 Bonfim, 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 continued support of Bastien Loloumb of Zuntabawe and Faustino Oliviera, Director of the botanical garden at Bom Sucesso. Special thanks for the generosity of private individuals, 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, and Mrs. Sheila Farr Nielsen for helping make these expeditions possible. Tax-deductable donations in support of this work can be made to “CAS-Gulf of Guinea Fund.”


February 18, 2011

The Race: On Rocket Frogs and Millipedes

First, some great news on the academic front.  One of the graduate student participants on GGI back in 2001 just completed his PhD at the University of California, Berkeley. Meet Dr. Joel Ledford, newly-minted world authority on spiders and explorer of Gulf of Guinea biodiversity.  In the picture below, he is holding “bubba,” one of the three endemic tarantula species of São Tomé.

DR. Joel Ledford with Hysterocrates apostolicus.   D. Lin phot. GGI

Readers of this blog already know that when we talk about biodiversity, we are talking about everything living, not just the big fancy stuff like birds and giant begonias.  Many of the secrets of island evolution are to be unlocked through the study of small organisms.   I have just received some preliminary news from Dr. Didier Van den Speigel of the Royal Central African Museum in Belgium.  After Dr. Rowland Shelley of the North Carolina State Museum did a preliminary analysis of our GG IV millipede specimens, we sent them to Didier, a specialist on this group in the Old World.  Rowland had concluded that we had at least one new species of the genus Globanus from each island.

A millipede (not Globanus) phot.  from cephalopodiatrist.com

Didier has examined material from other museums and has concluded that, in fact, the genus Globanus itself is endemic, found nowhere else in the world but the islands of São Tomé and Príncipe.  We are still unsure of how many species our GG IV material represents, but what seems evident at this time is that they are all each other’s closest relatives.  Drs Van den Speigel and Shelley are in agreement that this turns out to be the case, it would represent a “species swarm,” much like the endemic earthworms of São Tomé (see July 2010 blog “Nightmares….”, for an explanation).  The work continues……

In my memorial to Abade last month, I described one of our early unsuccessful  searches for Newton’s rocket frog during GG I.

Newton’s rocket frog, Ptychadena newtoni.  D. Lin phot.  GGI

This widely distributed genus of about 50 species is found throughout sub-Saharan Africa and distinguished by a sharp snout, paired vocal sacs (lower arrow),  distinctive glandular ridges on the back (upper arrow) and very long legs.  In fact a member of this group from South Africa holds the world record frog jump of over 33 feet (10m)!  P. newtoni is one of São Tomé’s classic “island giants; at 76 mm (not including legs) a  São Tomé female is much larger than any specimens of mainland species on record.

After days of visiting known localities mostly in and near the town of São Tomé and finding them dry, heavily disturbed and frogless, one rainy evening two young boys led us to a vacant lot less than 200m from where we were living, and there were the frogs!   Ultimately, genetic analysis of these frogs established that they were, indeed, full endemic species, but also led John Measey, currently of South Africa, and a group of us to publish our rafting hypothesis in the Journal of Biogeography (2007 – see earlier blogs).

Our difficulty in finding this species in the northern lowlands of São Tomé (all of the known localities at the time) suggested to me that this may be the only endemic amphibian species on São Tomé that might be endangered due to human development.

Series of Ptychadena newtoni larvae from Java, Sao Tome.  RCD phot. GG II

However, during GG II we found a series of tadpoles at Java (elevation 595m) which we later determined belonged to this species (although no adults were seen).  Tadpoles are typically identified by various external characteristics, but especially by fine structures of the mouthparts. The drawings below are taken from a nearly completed manuscript that attempts to technically describe the tadpoles (larvae) of all the endemic island frog species; it has not been published because, even after all these years, we have still not found the larvae of the Príncipe giant treefrog, Leptopelis palmatus!

P. newtoni mouthparts from unpublished manuscript.

P. newtoni left lateral view from unpublished manuscript.

Our discovery of the Java larvae indicated that Newton’s rocket frog is not necessarily present only in the heavily developed northern lowlands.

Recently, a young biologist, Hugulay Maia, whom we first met during GG IV has found some new P. newtoni localities.

Hugulay Maia of ABS, doing tree work.  unknown photographer]

Hugulay is a member of Associação dos Biologos (ABS), a local group of biologists involved in biodiversity efforts on São Tomé. The group is led by Dr. Alzira Rodrigues of the Polytechnic Institute; other members you have met in this blog are Angus Gascoigne and Victor Bomfim.

Current P. newtoni localities: green = to 1992; pink = to date

Now, thanks to Hugulay’s observations (and photographs) we have a somewhat better idea of the distribution of Newton’s rocket frog.  Earlier known localities are in green and were published by a Swiss worker in 1992; our GG II Java locality and Hugulay’s new localities are in pink.  Hugulay’s data confirm that the species is not confined to the north.  He has observed it at Colonia Açoreana (labeled) and two more southerly spots, Angra Toldo Cavaleite and Roça Alinhança.

The data are still thin, but we can at least infer that Ptychadena newtoni is more widespread than originally thought.  Almost all of the mainland species breed in relatively still or slow-moving water, and it is reasonable to assume this is the case with Newton’s rocket frog.  All of the old localities (in green) are associated with lowland reaches of major water courses: the city localities are in the Agua Grande drainage; Hugulay Maia’s new records are all from the Ribeira Afonsa drainage, and the Diogo Vaz locality (green symbol in the NW) is from the small Agua Anambo, which parallels the larger, much faster Rio Maria Luiza to south.  Java our highest locality is on the Rio Abade, but the tadpoles were collected in a man-made pool in a roadside, partially dry creek bed, not in the river itself.   To assess the actual status of Newton’s rocket frog, I think we just need to look more closely in bodies of slow or still water along major rivers throughout the island.

The Parting Shot:

Dr. Joel Ledford: Spider hunters in repose. D. Lin phot.   GG I

PARTNERS

We gratefully acknowledge the support of the G. Lindsay Field Research Fund, Hagey Research Venture Fund of the California Academy of Sciences, the Société de Conservation et Développement (SCD) and Africa’s Eden for logistics, ground transportation and lodging, 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 continued support of Bastien Loloum of Zuntabawe  and Faustino Oliviera, Curator of the Herbarium at Bom Sucesso. Special thanks for the generosity of private individuals, 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 for helping make these expeditions possible.  Our expeditions can be supported by donations to “California Academy of Sciences Gulf of Guinea Fund”.



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