Kx (382 Git: Sy, 
Bull. nat. Hist. Mus. Lond. (Zool.) 68(1): 13-18 
Issued 27 June 2002 

A new species of freshwater crab (Brachyura, 
Potamoidea, Potamonautidae) from Principe, 
Gulf of Guinea, Central Africa 

NEIL CUMBERLIDGE 
Department of Biology, Northern Michigan University, Marquette, Michigan 49855, U.S.A. 
PAUL F. CLARK 
Department of Zoology, The Natural History Museum, Cromwell Road, London, SW7 5BD, U.K. 
JONATHAN BAILLIE 
Institute of Zoology, Zoological Society of London, Regents Park, London NWI 4RY, UK. 

CONTENTS 
INTER CNHI ECVE aes «once <scnta soe dae achazeencsesttealcesvisesesasscctereacentwocsaversivesdées 
SVSEPMIARI CHA CO OUR can agreean con tsav cuscseeyaussaesaayssctascencatcunsasatetecatyacrs 
PDHUIGIDE SPaTlOVs avavasucs Cetbaattacscyedesuarsisasvesacesinnessesaaseastivedsasses 
BC Old eiGalINGte si, Aer bircra te ict Nake asdse pod cent vaahiew dnalnsctanedenoss 
PNG KM OWIEC SCMIEMIS 5 a5: ceccncecateastuennesuaswenoxeoessentrssendetoses desinasvacuaene 
IN STETENCES yensuanates. deucnececMOa chav cas tardngassteedinn ccconsvscauisvaysVastnets tab dss 
SYNOPSIS. 
PASE S CEO oS TEL CR CDCOUTEL SRCEEL ERRCCE CePA RED Pe aro PCE Ee sere Ee CE OE 13 
wagebederan vscleaayntsme spas qeescsg ts Sack vaMonaa\ vc ov sii wastnns saute cesusvavaueervadades 13 
aaes dupes Sanda nabs sue e ace caste ooneBenae a catean etade aicee teas at Lisisncr sno aanede Ae 13 
Gu catscon tai nase gress vatreetnensnnstne > pise ccupeentaanesiscate tee scvsts'sSudeunesctesauess 17 
Bee BR ea ese n a NER EE a atiae See es ace cane RE ERS «wee nance os Read aher kone Manone 17 
waatt as haps ae ska ac Wtanhtane sales en des spt (oases wide cas av tras eee ay 17 
A new species of freshwater crab of the genus Potamonautes Macleay, 1838 is described from Principe (Democratic 
Republic of Sao Tomé and Principe), an island in the Gulf of Guinea off the coast of Central Africa. The specimens were collected 
during a recent zoological expedition by the Zoological Society of London. This is also the first record of a freshwater crab on 
the island of Principe. 
INTRODUCTION 
The freshwater crabs reported on here were collected during a 
zoological expedition to the island of Principe, made recently by the 
Zoological Society of London. The island of Principe, together with 
the island of Sao Tomé, constitutes a small independent country 
(The Democratic Republic of Sao Tomé and Principe) in the Gulf of 
Guinea. Principe is the second in a chain of volcanic islands that 
make up the Atlantic Ocean Islands group, that lies off the coasts of 
Cameroon, Equatorial Guinea and Gabon. The other islands in this 
group are Bioko, SAo Tomé and Annobon. Bioko is closest to the 
mainland and has two species of potamonautid freshwater crabs, 
Sudanonautes floweri (De Man, 1901) and S. granulatus (Balss, 
1929), both of which are also found in nearby Cameroon 
(Cumberlidge, 1993, 1995, 1999). Sao Tomé is the third island in the 
group, and has one endemic species of freshwater crab, Potamonautes 
margaritarius (A. Milne-Edwards, 1886). There are no records of 
freshwater crabs occurring on Annobon, the fourth island in the 
chain, and the furthest from the mainland. 
Until the present report, freshwater crabs were not known to be 
present on Principe. The new species from Principe was collected 
from streams and nearby land in cloud forest in the remote roadless 
highland region in the southwest part of the island. The new species 
is compared to Potamonautes anchietae (De Brito-Capello, 1871) 
and to P. margaritarius, but differs from each in a number of 
important characters (Bott, 1953, 1955, 1964). Although the speci- 
mens from Principe are both subadult females, and ideally an adult 
male is needed to make a definitive identification, a description is 
© The Natural History Museum, 2002 
nevertheless provided here, based on several unique somatic 
characters of the specimen. Characters of the gonopods, male abdo- 
men, and male chelipeds will be described when more material 
(including an adult male) becomes available. 
Figures were prepared using a camera lucida, and the specimens 
were deposited in The Natural History Museum, London, U.K. 
(BMNH). Abbreviations: cw, distance across the carapace at the 
widest point; cl, carapace length measured along the median line, 
from the anterior to the posterior margin; ch, carapace height, the 
maximum height of the cephalothorax); fw, front width measured 
along the anterior margin; s, thoracic sternite; e, thoracic episternite; 
s4/s5, s4/s5, s5/s6, s6/s7, s7/s8, sternal sulci between adjacent 
thoracic sternites; s4/e4, s5/e5, s6/e6, s7/e7, episternal sulci between 
adjacent thoracic sternites and episternites; P1—P5, pereiopods 1-5, 
al—a6, abdominal segments 1-6, a7, telson of the abdomen. 
SYSTEMATIC ACCOUNT 
Family POTAMONAUTIDAE Bott, 1970 
Genus POTAMONAUTES MacLeay, 1838 
Potamonautes principe sp. nov. 
(Fig. 1) 
MATERIAL EXAMINED 
Holotype. BMNH 2001.6907. 1 subadult female, cw 40.5, cl 27.5, 
