Harvestmen of French Guiana

Jérôme Murienne

Collecting trips have been conducted in various locations throughout French Guiana.

This dataset was developed to determine the current distribution patterns of harvestmen species at the scale of French Guiana. Thus locations to be sampled were selected to maximize the geographical coverage. For some collecting trips (e.g. Saül 2013), a specific design was implemented to sample over three topographic units: hilltop, slope and seasonally-flooded bottomland.

Data for this resource have been obtained within the framework of grants DIADEMA and PHYLOGUIANAS from the Labex CEBA (Laboratoire d'Excellence Center for the Study of Biodiversity in Amazonia). CEBA is funded by "Investissement d'Avenir" grant managed by the French National Research Agency (ANR) under grant number ANR-10-LABX-25-CEBA.

Study sites were located throughout French Guiana.

The following techniques were used, however not all techniques were used on every collecting site and sampling design might not be similar among these sites.

Pitfall traps: 20 plastic cups with 70% ethanol were distributed within a 0.5 hectare plot and exposed for 72 hours.

Winkler: all the litter and superficial soil layer from 1 m² was concentrated with the aid of a hand-sieve and sorted using a winkler apparatus during 2 days.

Litter manual sorting: all the litter and superficial soil layer from 1 m² was concentrated with the aid of a hand-sieve and sorted by hand using a plastic square plate.

Beating: vegetation above knee-level was sampled using a 1 m² beating sheet.

Sweeping: vegetation below knee-level was sampled using a sweep net.

Manual nocturnal ground search: samples are collected during the night on the ground or at the base of trunks.

Manual search in and under the dead wood. Samples are collected by searching in and under the dead wood pieces or the dead trunks on the ground.

GPS coordinates were obtained using a GPSmap 60CSx device or similar. Such devices report coordinates accuracy using the CEP50 (Circular Error Probability), meaning that there is only 50% probability that a reported position would be within a distance of X meters to the real position. Considering other sources of GPS errors (such as ionosphere delay and signal multi path) we estimate the accuracy of the coordinates to be around 30 meters at a 95% confidence level.

Initial specimens identifications to the family level (for all families) and genus level (for Agoristenidae, Stygnidae and Gonyleptidae) have been checked by Ricardo Pinto-da-Rocha. Validity of the taxonomic names used was checked against the Encyclopedia of Life (http://www.eol.org) and the GBIF backbone taxonomy (http://www.gbif.org/dataset/d7dddbf4-2cf0-4f39-9b2a-bb099caae36c). Future validity checks could use the "World Checklist of Opiliones species", once it is published in its entirety (Kury et al. 2014).

After collection, samples are sorted and placed in individual tubes containing 95% ethanol with a unique identifier until further processing in the laboratory. Codes are based on locality, collection date, collection method followed by a unique number as in GF140308HC001-07 which indicates that the specimen was collected in French Guiana (GF) on 2014-03-08 (yyyy-mm-dd), and hand collected (HC). Collection method codes include sweep net (SN, SND or SNN), beating (BND or BNN), pitfall (PT), winkler (WK, WKD or WKN). When specimen collection was part of a larger field expedition, we kept the original codes that might not follow this rule (as in SL13-1208-OP01 collected in Saül).

Collecting information for each specimen is databased in an online Voseq database (Peña and Malm 2012) hosted by the EDB laboratory (Fig. 1).

Figure 1.  

Example data entry of our online database (http://edbase.ups-tlse.fr with restricted access) holding the "Harvestmen of French Guiana" dataset. The database can be downloaded as a spreadsheet at: http://130.120.204.55:8080/ipt/resource.do?r=harvestmen_of_french_guiana or at: http://www.gbif.org/dataset/3c9e2297-bf20-4827-928e-7c7eefd9432c.

Specimens are photographed using an Olympus DP20 mounted on a Leica MZ16 binocular and pictures are stored in the database.

For each specimen, 1 or 2 legs are kept in a separate vial and stored at -20°C for further molecular investigation.

Specimens are initially curated at the EDB laboratory by J. Murienne and can be deposited in museums for further taxonomic study. For example, specimens of Sclerosomatidae have been sent as gift to the Museum of Comparative Zoology (MCZ) at Harvard University, Cambridge USA, to be investigated by Ana Lucia Tourinho. The current localisation of the specimens (either at EDB or in museums) can be found under the "disposition" field.

The sampling area is delimited by the current administrative boundaries of the French Guiana territory (Fig. 2). To the East, the Oyapock River delimits the frontier with Brazil. To the West, the Maroni River delimits the frontier with Surinam. This is an important detail as the delimitation of the territory has not been constant throughout history and a large portion of northern Brazil was disputed between France and Brazil during the 19th century. Several species described or reported from French Guiana during the 19th century and early 20th century (see Kury 2003) are actually located in Brazil. Even though French Guiana is an overseas department and region of France, all occurrences have been recorded under the "French Guiana" country to comply with the ISO 3166-1 standard.

Figure 2.  

Geographical coverage of the dataset and collecting localities as of 2014.

2.09 and 5.85 Latitude; -51.53 and -54.61 Longitude.

This database is devoted to all harvestmen species inhabiting French Guiana. Little is known about the taxonomy of the group in French Guiana but some information are available in Kury (2003) for Laniatores and Benavides and Giribet (2013) for Cyphophthalmi. Identifications to the family level were conducted based on Kury and Pinto-da-Rocha (2002) and Pinto-da-Rocha et al. (2007)  (Fig. 3). Three families are here reported for the first time in French Guiana, namely Agoristenidae, Fissiphalliidae and Icaleptidae. Identifications of Stygnidae to the species level were conducted based on Pinto-da-Rocha (1997).

Figure 3.  

Taxonomic coverage at the family level of the "Harvestmen of French Guiana" dataset as of 2014.

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International Public License. http://creativecommons.org/licenses/by-nc/4.0/. Users of this resource should also comply with the CEBA data sharing agreement available here: www.labex-ceba.fr/assets/CEBA_Data_Sharing_Agreement_nov2013.pdf