Shrews | Island Biodiversity Race

The Race: New Species or What’s in a Name?

Category: Biodiversity, Sao Tome, frogs, mushrooms, shrews | Date: Aug 18 2009 | By: islandbiodiversityrace

Ever wonder why biologists use weird, hard-to-pronounce names for animal and plant species? Well, it all started with Carl Linnaeus, the famous Swedish 18^th Century botanist pictured below.

In the 10^th edition of his great work, Systema Naturae (1758), Linnaeus established a system wherein every living species is given but a single scientific name made up of two parts: the Genus (always capitalized) and the species (always lower case and both are always italicized). Among animals, no two species ever have the same name, and this is true among plants, as well. Thus we modern humans are scientifically referred to only as Homo sapiens. In Linnaeus’s day, most scientists wrote in Latin or Greek, thus it was an early tradition to establish these names in those ancient languages. Now, naming of new species is tightly regulated by The International Congress of Zoological Nomenclature (ICZN; the botanists have the ICBN). A specific scientific name avoids confusion… here is an example:

The common English name of the critter above is red rattlesnake, or red diamondback rattlesnake; some locals might call it a “red buzzworm!” In French it would be called un serpent á sonnettes rouge; in German: eine rote klapperschlange and if an East African ever saw one, he might call it nyoka sumu nyukundu. See the problem? Not only different base languages, but regional differences in common names serve to muddy the waters. However, the scientific name of this critter is Crotalus ruber, and regardless of their native languages, scientists will always know exactly what species is being discussed. Taxonomists usually try to come up with a name that is descriptive of the species; in this case, Crotalus ruber translates roughly from the Latin as “red bell-ringer,” an obvious reference to its color and the sound made by the rattle.

The Sao Tome shrew: Crocidura thomensis (R. Lima phot, 2009)

Here is another example– the supposedly endemic shrew we are just beginning to study is called Crocidura thomensis, which means “yellow-tail from Thomas [=São Tomé]”. Probably the first species described in the genus Crocidura had a yellowish tail, although C. thomensis clearly does not.

The Oceanic Treefrog, Hyperolius molleri (Weckerphoto GG III)

Scientists may also name species in honor of the person who first collected the specimen; such is the case with the Oceanic treefrog, Hyperolius molleri, found on both São Tomé and Príncipe, M.A.F. Moller was the late 19^th Century explorer who first collected the frogs and brought them to Portugal where the species was named in his honor at the University of Coimbra.

Sao Tome puddlefrog, Phrynobatrachus leveleve (Weckerphoto GG III0

Taxonomists have a fair amount of latitude in the choice of words and meanings for scientific names although they are usually Latinized. As an example, Josef Uyeda, Breda Zimkus and I chose Phrynobatrachus leveleve as the new name for one of our own new species of frogs from São Tomé. Phrynobatrachus is an old generic name and actually means “toad-frog;” as to the meaning of leveleve, here is a quote from our paper: The phrase, “leve leve,” generally meaning “easy, easy” or “lightly, lightly” has also been translated by Henrique Pinto da Costa, former Minister of Agriculture, as “calmly, surely.” In our opinion, all three definitions describe the delightful, easy-going demeanor of the citizens of The Republic of São Tomé and Príncipe….it is with the hope that the citizens of this tiny African nation will maintain their ecological heritage and cheerful outlook on life that we name this diminutive endemic anuran. Thus, we named the new species in honor of the attitude of the island citizens.

Illustration by H. Heatwole, 1970

Scientists are also known to inject humor into scientific names, on occasion. The image above is a composite plate from a scientific publication. By way of explanation, many American scientists receive support for their work from our National Science foundation, known universally to us over here as “NSF”. Look at the upper-most image of a frog known scientifically as Physalaemus enesefae… if you are an English speaker, pronounce the species name slowly and you’ll get the humor.

Now for the fun stuff: here is a photo of our latest new species from São Tomé, a mushroom we discovered on the trail up to Lagoa Ameliaduring GG II in 2006. It was formally described just last month in the journal MYCOLOGIA, and Drs Dennis Desjardin and Brian Perry named it after me. It is called Phallus drewesi meaning (literally) Drewes’s penis!

Phallus drewesi Desjardin & Perry 2009 (B. Perry phot. GG III)

As you can see, these fungi are shaped very much like a mammalian penis… they usually grow upright from the forest floor, smell terrible and attract flies! The flies act as vectors disperse the fungus’s spores!

Dr. Brian Perry with a Principe Phallus (RCD phot. GG III)

Members of the genus Phallus can grow quite large. Above is an image of Dr. Brian Perry, one of the describers, holding an example of Phallus atrovolvatus from Príncipe –a rather average sized Phallus.

The author with Phallus drewesi on Sao Tome (Weckerphoto, GG III)

Above is a picture of me holding a couple of examples of Phallus drewesi in 2008, and as you can see, they are quite small! Not only that, but so far as is known P. drewesi is the second smallest species in the world! And, it grows limp! Not proudly erect from the forest floor!

It has been hard for some of my non-scientists to understand what an incredible honor this is. Dennis, Brian and I are good friends and colleagues; in fact, Dennis and I play jazz together as often as we can and serve on the same university faculty.

The author and Dr. Desjardin at Praia Francesa. (Weckerphoto GG III)

It is a great honor because having a species named for you confers a form of immortality. Regardless of what the species is, the scientific name lives on as long as there is science. This is even the case even if decades from now, another scientist learns that this species already has a name – Phallus drewesi lives on in the botanical literature as a synonym. Scientists keep track of all names formally ascribed to a species, whether valid or not. So, yes, it is a wonderful thing to have something named after you, whatever it may be!

Here’s the parting shot:

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) 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 Bardero of the Ministry of Environment, Republic of São Tomé and Príncipe for permission to export specimens for study, and the continued support of Bastien Loloumb of Monte Pico 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 and Mr. and Mrs. Michael Murakami for helping make these expeditions possible.

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The Race: Taming of the Shrew (and updates)

Category: Biodiversity, Gulf of Guinea, Island endemics, Sao Tome, biogeography, flowers, mushrooms, principe, shrews | Date: Jun 24 2009 | By: islandbiodiversityrace

Things have been very busy.

Our flower people, Dr. Tom Daniel and Rebecca Wenk have been very active. Rebecca successfully completed her M.Sc . degree at San Francisco State University, based in part on plants she collected in the islands during GG III (A). She then published her research, with Tom, in the latest Proceedings of the California Academy of Sciences; the publication includes a special treatment of the genus Elytraria – E. mariginata is the little flower that Rebecca finally found high up on Pico Papagaio on Príncipe that was so exciting and which we reported last May. (See “News from the Flower people”).

Rebecca among the giant Begonias. Lagoa Amelia. Wenk camera: GG III.

Tom is nearing completion of his monograph on the acanthus (shrimp) flowers of São Tomé and Pr<!–[if gte msEquation 12]>í<![endif]–>ncipe. He is now collaborating with Estrela Figueiredo, a Portuguese botanist who has been on the islands many times and has added much to our knowledge of the botany of the Gulf of Guinea as a whole There are several species of the Acanthaceae found only on São Tomé and Príncipe and one (Heteradelphia paulowilhelmia) which may be endemic at the genus-level. We found this beautiful flower in the middle of Lagoa Amelia at 1400 m. during GG III.

Heteradelphia paulowilhelmia. Lagoa Amelia. Weckerphoto: GG III

Wes Eckerman (photographer) Rebecca and Tom at Lagoa Amelia. RCD phot: GGIII

Another species in Tom’s group that is of particular interest to me personally is an acanth called Justicia thomeensis. This flower is known only from São Tomé and has not been collected since the late 19^th Century – the original collector did not provide detailed locality data, and we have not found it on the islands yet. We hope it is not extinct, or that it was not actually collected somewhere else. Tom has examined the original dried specimens in Coimbra; it is perfectly valid, and he is re-describing the species. Another botanist named Hedrén examined this material, and in a 1989 study found that J. thomeensis is more closely related to a group of species in East Africa than to any in nearby West Africa. I am finding the same strange disparate distribution patterns among my island frogs.

Justicia relationships. RCD

On the crustacean front, Alex Kim, our freshwater shrimp colleague (see January and March blogs) has decided to attend Harvard for his undergraduate studies, and this summer he is doing fieldwork on prawns in Puerto Rico. He tells us that the São Tomé specimens collected for him earlier this year by the marine group “..represent at least two species which, based on morphology, have clear affinities with New World forms. DNA analysis is still ongoing, but the geological youth of these prawns leads me to suspect that we will soon have genetic evidence of trans-Atlantic larval dispersal.” Pretty impressive stuff for an incoming freshman.

A New World prawn. Alex Kim phot.

A few months ago I had an opportunity to lecture on some of the scientific results of our Gulf of Guinea Island expeditions to a group of biologists at international meetings in Sardinia; afterward in Spain, I met one of the foremost experts on bats, Javier Juste, of Institute Doñana in Seville who has also worked on the islands and has discovered some of the same strange evolutionary relationships that we have. We are about to send him bat tissues from our GGI collection for DNA extraction.

7th Congresso Nazionale, Societas Herpetologica Italica. Sardinia. C. Corti phot.

In earlier blogs, we discussed the fact that mammals make poor dispersers over saltwater barriers; except for some bats, mammals simply cannot survive long enough to colonize oceanic islands. This is because we mammals have to eat regularly in order to maintain constant body temperatures –without “stoking the furnace” by eating regularly, mammals quickly die of exposure. This is specially the case with shrews; because of the ratio of their tiny body masses to their surface area, shrews lose heat faster than any other mammal, and a shrew has eat almost constantly, or it dies of hypothermia. It is perhaps a testimony to the great geological age of São Tomé and Príncipe that shrews appear to have, nevertheless, successfully colonized both islands! If the two species are indeed valid and occur naturally (not brought to the islands accidentally through human agency), then these may be the only oceanic island shrews in the world.

The Sao Tome shrew (Crocidura thomensis). R. Lima phot. 2009

To our knowledge, the photographs above and below are the first ever published of the supposedly endemic São Tomé shrew, Crocidura thomensis. The photographs were taken by Ricardo Lima, a doctoral candidate at the University of Lancaster who is studying the environmental effects of various agro-forestry techniques on São Tomé. Ricardo tells us that the shrews are not at all rare; in spite of this, we don’t know much about this little critter, nor the one on Príncipe. The São Tomé species was first discovered in 1886 by the great Portuguese explorer, Francisco Newton and described in 1887.

C. thomensis. R. Lima phot. 2009.

The relationships of these small island insectivores were not assessed until nearly 100 years later by Heim de Balsac and Hutterer in 1982. These authors concluded (on morphological evidence) that the São Tomé shrew was a full endemic species, and that the Príncipe form was an endemic subspecies of Fraser’s musk shrew (C. poensis) which is widespread on mainland Africa.

Ricardo Lima and friends, crossing the Rio Lemba, Sao Tome. 2009.

Now, we are in the exciting position of being able to test these assumptions using modern genetic techniques; just how closely related are the two shrews, based on DNA sequence? Did these mammals arrive naturally by rafting, as we suggest for the amphibians? Perhaps millions of years ago? Or were they hitchhikers on an old Portuguese galleon a couple of hundred of years ago? We hope to find out.

Aspergillus dykowskii and Sarophorum palmicola on monkey pod cacao; Lagoa Amelia. D Lin phot. GG II

Finally, our mycologists have a huge job. As you know before our expeditions began back in 2001, there were only four species of mushrooms known from São Tomé, and Príncipe had never been sampled. Now, after Dr. Dennis Desjardin’s work on GG II (2006) and his subsequent return with Dr. Brian Perry during GG III last year, we now have 225 species (including 75 listed for the first time on Príncipe). Many of these are probably new to science and it will be a major effort to fully analyze the entire collection. But Dennis and Brian took the opportunity to describe one of the new species separately. It has just been formally published in the journal Mycologia, and they have named it after me! It is a weird looking thing, and I will describe the whole process (including the humor sometimes involved) in the next blog.

Here’s the parting shot: