Filling a gap in the distribution of Taulidesmella tabatinga (Polydesmida, Pyrgodesmidae): a new record from the upper Amazon River, Brazil

The millipede species Taulidesmella tabatinga is known from the border of Brazil with Peru and Colombia, Iquitos (Peru), and environs of Manaus (Brazil). Based on freshly collected material during the rainy season in 2014 along the Amazon River upriver from its confluence with the Negro River, we report a new record of T. tabatinga in floodplain forests in the municipality of Alvarães, Amazonas state (Brazil), filling a gap of 1,000 km between its previously known occurrence points. This record indicates that T. tabatinga is likely widespread along both margins of the upper Amazon River, mostly associated with tree trunks and litter of riparian and floodplain forests.


PALAVRAS-CHAVE: floresta amazônica, Neotrópico, floresta inundável, Diplopoda
The millipede family Pyrgodesmidae is distributed in tropical regions, and marginally in Europe, northern Africa, southern USA, Japan, Taiwan, and central China (Enghoff et al. 2015).The family is composed of nearly 170 genera, mostly monotypic, and 400 species (Hoffman 1980;Enghoff et al. 2015).In Brazil, the highest species richness is found in the southeast region, mainly in the states of São Paulo and Rio de Janeiro (Schubart 1944(Schubart , 1945;;Silvestri 1948).In northern Brazil, they are known mainly from the environs of Manaus, state of Amazonas (Hoffman 1985;Golovatch 1996Golovatch , 1997Golovatch , 1999Golovatch , 2001;;Golovatch and Adis 1998;Golovatch and Sierwald 2001).The diversity and richness of the family in the Neotropics are still poorly known, primarily due to the scarcity of specialists in the group and lack of sampling.
The genus Taulidesmella Kraus, 1959 is a pyrgodesmid endemic to the Neotropical region characterized by the absence of ozopores, 20 body rings in adults, and males with gonopods deeply bipartite and telopodite suberect (see Figure 31 in Kraus 1959;Figure 9 in Golovatch and Adis 1998).To date, the genus is known from its type species, T. chanchamayo Kraus, 1959, collected in the Andean region of Peru (Kraus 1959), and T. tabatinga Golovatch and Adis, 1998, known from Tabatinga, the environs of Manaus (Brazil), and Iquitos (Peru).Despite the scarce occurrence records of ACTA AMAZONICA the genus, the biology and ecology of T. tabatinga is relatively well documented.Adults of this species living in floodplain forests can climb tree trunks right before inundation events, aggregating in groups of around 200 specimens on the bark surface up to 2 m above the water-level during the day.The species shows physiological alterations related to flood tolerance, and foraging adaptations related to the presence of elongated teeth of pectinate lamellae coated by green algae (Golovatch and Adis 1998).
Based on freshly collected material along the Amazon River upriver from its confluence with the Negro River during the rainy season in 2014, we report a new record for T. tabatinga, filling a gap of around 1,000 km between its previously known occurrence points in the Amazon region.
Six specimens (Figures 1 and 2) were collected in the municipality of Alvarães, state of Amazonas, Brazil (Figure 3), in an area of floodplain forest about 20 km from the urban center of Tefé.The material examined is deposited in the zoological collection of Instituto Butantan, São Paulo, Brazil (IBSP).The specimens were identified according to the description provided by Golovatch and Adis (1998).Photographs were taken with a Leica DFC 500 digital camera mounted on a Leica MZ16A stereomicroscope at IBSP (São Paulo, Brazil).Focus-stacked images were composed with Leica Application Suite (ver.2.5.0,Leica Microsystems, Canton de Saint-Gall, Switzerland).The geographical coordinates and ecological remarks were obtained directly from the original label of all the samples.The distribution map was prepared using the software DIVA-GIS 7.5.0(Hijmans et al. 2001) with the locality data provided by the examined material and original description.
Distribution.Taulidesmella tabatinga has been reported from environs of Manaus, the border of Brazil with Colombia and Peru (Tabatinga), and Iquitos (Nanay River, Peru) (Golovatch and Adis 1998).The new record from Alvarães fills a gap of distributional range by approximately 1,000 km (in a straight line) between the occurrence points of Tabatinga and Manaus, along the floodplain forests of the upper and central Amazon River (Figure 3).The record reported in here indicates that T. tabatinga is likely widespread along both margins of the upper Amazon River, as suggested by Golovatch and Adis (1998).Further surveys are likely to reveal the frequency of occurrence of this and other species of Taulidesmella in the region.

Figure 1 .
Figure 1. Adult female of Taulidesmella tabatinga (IBSP 8296).A -Dorsal view of whole body; B -Anterior region, in ventral view; C -Posterior region, in ventral view; D -Midbody rings, in dorsal view; E -Detail of midbody rings, in dorsal view.Scale bars: A = 1 mm; B, E = 0.3 mm; C-D = 0.5 mm.This figure is in color in the electronic version.

Figure 2 .
Figure 2. Adult male of Taulidesmella tabatinga (IBSP 8297): A -Ventral view of midbody rings with gonopods fully exposed; B -Detail of gonopods fully exposed; C -Left gonopod, in ectal view; D -Left gonopod, in mesal view.Scale bars: A = 0.5 mm; B = 0.3 mm; C-D = 0.2 mm.This figure is in color in the electronic version.

Figure 3 .
Figure 3. Distribution map of Taulidesmella tabatinga records in the Amazon region.The red triangles refer to the previously known records and the yellow star to the new record.This figure is in color in the electronic version.