Tarantula species rediscovered after 100 years
A new record for Honduras of a tarantula species is one of the outcomes of a survey carried out in Cusuco over summer 2011. The species has remained an enigma for more than a hundred years.
Protection of tarantulas
In 1994, concern about the vulnerability of Mexican tarantula populations to human exploitation for the exotic pet trade led to the protection of the entire genus Brachypelma under the Convention of International Trade in Endangered Species (CITES). In 2008, 14 Indian tarantula species were added to the IUCN red list of threatened species.
Nevertheless, tarantulas in general remain amazingly under-studied, despite their high public profile. Greater study of these exceptional spiders is urgently needed to help understand their ecological role as top invertebrate predators. Tarantulas are useful as bio-indicators of habitat quality and have potential as important sources of useful pharmacological compounds, most notably their silk and venom.
Taxonomic research remains vital
Because developing countries tend to allocate scientific resources to applied projects – such as agricultural improvements – arachnids, including spiders, in Central America have been little studied. This is unfortunate because, as predators, arachnids have important roles to play in ecosystems, including agricultural ones.
Because of their size and their prominence in the public imagination, one might expect tarantulas to be relatively well-known members of tropical ecosystems… this is not the caseIn one of the four arachnid volumes of the Biologia Centrali Americana, F O Pickard-Cambridge described Eurypelma longipes 1897 [Vol 2, p 21]. He also listed several coffee plantations as collection localities in Alta Verapaz, Guatemala. This cooler region of moisture-laden highlands contains similar habitats to those of northern Honduras.
This species was subsequently used to establish a new genus Citharacanthus (Pocock 1901). Since then, despite occasional poorly supported claims of rediscovery, C. longipes has remained an enigma. In general, the genus is poorly known, with other alleged species found in Guatemala, Belize, Cuba and Mexico. Yet, it is vital to understand the first described species (C. longipes) to correctly define the attributes of the genus Citharacanthus.
Rediscovery of C. longipes in Cusuco Park
In the summer of 2011, the first Operation Wallacea surveys of arachnids were carried out in the Parque Nacional Cusuco, Honduras. Megan Lock, a dissertation student from Maryville College, US worked alongside Dr Stuart Longhorn from the National University of Ireland, with help from many others, including Thomas Creedy, Imperial College (UK), Kevin Sagastume, National Autonomous University of Honduras, and Max Kratschke, Edinburgh University (UK).
We discovered that two species of tarantulas coexist inside the protected zone, both similarly coloured, but differing in size. Specimens of both species were taken back to the UK for comparison with museum specimens, and by careful study against the original specimens described in the Biologia Centrali Americana, the larger species was identified as Citharacanthus longipes (F O P-Cambridge, 1897). Previously only known from the old type specimens collected in Guatemala, this is an important rediscovery, and a newly recorded species for Honduras.
The smaller tarantula species in Cusuco was identified as another species of Citharacanthus, probably C. livingstoni Schmidt and Weinmann 1996. This species was first described from pet-trade specimens collected in the nearby coastal Guatemalan town of Livingston, and is also known from Belize. Whether or not this second species identification is correct (we first await to examine the type specimens of C. livingstoni held in Germany to confirm), this will undoubtedly be another first record for Honduras.
Because of their size and their prominence in the public imagination, one might expect tarantulas to be relatively well-known members of tropical ecosystems. Our survey in Honduras shows this not to be the case. That we still know so little about such iconic animals is an indicator of how little we still know about tropical environments in general, and therefore, an exhortation to expand our efforts to catalogue and understand biodiversity.