Amazonian earthworm biodiversity is heavily impacted by ancient and recent human disturbance.

Despite the importance of earthworms for soil formation, more is needed to know about how Pre-Columbian modifications to soils and the landscape. Gaining a deeper understanding is essential for comprehending the historical drivers of earthworm communities and the development of effective conservation strategies in the Amazon rainforest. Human disturbance can significantly impact earthworm diversity, especially in rainforest soils, and in the particular case of the Amazonian rainforest, both recent and ancient anthropic practices may be important. Amazonian Dark Earths (ADEs) are fertile soils found throughout the Amazon Basin, created by sedentary habits and intensification patterns of pre-Colombian societies primarily developed in the second part of the Holocene period. We have sampled earthworm communities in three Brazilian Amazonian (ADEs) and adjacent reference soils (REF) under old and young forests and monocultures. To better assess taxonomic richness, we used morphology and the barcode region of the COI gene to identify juveniles and cocoons and delimit Molecular Operational Taxonomic Units (MOTUs). Here we suggest using Integrated Operational Taxonomical units (IOTUs) which combine both morphological and molecular data and provide a more comprehensive assessment of diversity, while MOTUs only rely on molecular data. A total of 970 individuals were collected, resulting in 51 taxonomic units (IOTUs, MOTUs, and morphospecies combined). From this total, 24 taxonomic units were unique to REF soils, 17 to ADEs, and ten were shared between both soils. The highest richness was found in old forest sites for ADEs (12 taxonomic units) and REFs (21 taxonomic units). The beta-diversity calculations reveal a high species turnover between ADEs and REF soils, providing evidence that ADEs and REFs possess distinct soil biota. Furthermore, results suggest that ADE sites, formed by Pre-Columbian human activities, conserve a high number of native species in the landscape and maintain a high abundance, despite their long-term nature.

Distribution and diversity of earthworms in different land use systems in Rio Grande do Sul, Brazil.

The southernmost state of Brazil, Rio Grande do Sul, includes both the Pampa and Atlantic Forest biomes, and covers an area of around 284 thousand km2. Since the last checklist for the state, published in 2012, many additional sites have been sampled. Hence, we provide here a full list of earthworm species and their distribution in different municipalities and land use systems in the state. Data were obtained from the literature, museums, and other earthworm collections and recent sampling efforts. Records for 19 additional species are reported here for the first time, raising the total to 78 species/subspecies currently known from Rio Grande do Sul, from the families Acanthodrilidae (5), Benhamiidae (3), Lumbricidae (13), Megascolecidae (11), Ocnerodrilidae (22), Almidae (2), Glossoscolecidae (18) and Rhinodrilidae (5). Alexidrilus Righi, 1971 is synonymized with Urobenus Benham, 1886, as both species in the genus (A. littoralis Ljungström, 1972 and A. lourdesae Righi, 1971) have similar morphology to the type species Urobenus brasiliensis Benham, 1886. Most of the native species/subspecies in the state (39), including an important number of new species, were found in native vegetation with lesser disturbance, such as swamps, native forests and pastures. On the other hand, the three peregrine and 27 exotic species (especially Pontoscolex corethrurus, Eukerria spp., lumbricids, megascolecids, Dichogaster spp., and Microscolex spp.) dominated in disturbed sites, such as compost piles, urban areas, rice and other crops, and cultivated pastures. Considering the geographic extension and the many unsampled sites in the state, further collection efforts are necessary and will certainly reveal new species, as evidenced here.

Earthworms from natural and managed ecosystems in Southern Bahia, Brazil.

The earthworms (Crassiclitellata) of the Northern Atlantic Forest region are poorly known, and many new species are expected to be found in the region. Hence, quantitative and qualitative samples were taken in the Atlantic Forest region of southern Bahia State, Brazil, at eight sites to assess species presence and abundance in different land uses (forests, pastures, plantations). Earthworms were also qualitatively collected at an additional eight sites. Only one to two species per site were found in quantitative samples, while qualitative samples generally resulted in higher species recoveries, with highest richness observed at the native Atlantic Forest of Veracel in Porto Seguro. Pontoscolex corethrurus (Müller, 1857) was the dominant species at all sites and in most land use systems, probably favored by human migration and agricultural activities; it was only absent in one primary forest site where native Ocnerodrilidae species predominated. In total at least 14 species were found of which eight were new, belonging to the genus Rhinodrilus and three new genera in the Ocnerodrilidae family (Pauqueba, Parabauba and Diplomoela). Contrary to sites in Southern and Southeastern Brazil, where many native species belong to the Glossoscolecidae family, in southern Bahia, Ocnerodrilidae species tend to be more prevalent, occupying various habitats. More intensive sampling of these habitats, including surface litter, in and under fallen logs and dead tree trunks, under rocks, in bromeliad leaf tanks and deeper soil layers is essential in order to properly characterize earthworm communities in Brazilian Atlantic Forests.

New Ocnerodrilidae genera, species and records from Brazil (Annelida: Crassiclitellata).

We describe three new species of Eukerria, six of Kerriona, one of Ocnerodrilus and two of Belladrilus (Clitellata: Ocnerodrilidae) from Brazil, mostly from wet habitats including bromeliad leaf axils, plus some from forest soils in Bahia state. We also provide new morphological and distribution data on Kerriona luederwaldti Michaelsen, 1924. We describe the new genus Pauqueba and its two new species, both from bromeliad leaf axils and forest floor litter in the state of Bahia. It has two pairs of calciferous glands, the balantine reduction of the male terminalia but spermathecae in ix, and no gizzard. The new genus Parabauba found in deeper (30 cm) soil layers is distinctive for the combination of two pairs of calciferous glands, a large gizzard in v, acanthodriline male terminalia, and no typholosole. The new genus Diplomoela from a mesic soil in Bahia is meronephric, unusually large for the Ocnerodrilidae, and has two well-developed gizzards.

A "Dirty" Footprint: Macroinvertebrate diversity in Amazonian Anthropic Soils.

Amazonian rainforests, once thought to be pristine wilderness, are increasingly known to have been widely inhabited, modified, and managed prior to European arrival, by human populations with diverse cultural backgrounds. Amazonian Dark Earths (ADEs) are fertile soils found throughout the Amazon Basin, created by pre-Columbian societies with sedentary habits. Much is known about the chemistry of these soils, yet their zoology has been neglected. Hence, we characterized soil fertility, macroinvertebrate communities, and their activity at nine archeological sites in three Amazonian regions in ADEs and adjacent reference soils under native forest (young and old) and agricultural systems. We found 673 morphospecies and, despite similar richness in ADEs (385 spp.) and reference soils (399 spp.), we identified a tenacious pre-Columbian footprint, with 49% of morphospecies found exclusively in ADEs. Termite and total macroinvertebrate abundance were higher in reference soils, while soil fertility and macroinvertebrate activity were higher in the ADEs, and associated with larger earthworm quantities and biomass. We show that ADE habitats have a unique pool of species, but that modern land use of ADEs decreases their populations, diversity, and contributions to soil functioning. These findings support the idea that humans created and sustained high-fertility ecosystems that persist today, altering biodiversity patterns in Amazonia.

Earthworm species in various land use systems in the Campos Gerais region of Lapa, Paraná, Brazil.

The Campos Gerais region of Paraná are on an ancient plateau of sandstone origin and are covered with a diverse vegetation including mainly grasslands and various types of Atlantic Forest (particularly Araucaria forest). The region represents an important natural capital for biodiversity conservation as well as for agricultural and forestry production. However, little is known of the species richness and diversity of soil macroinvertebrates in this region. In the present study we evaluated earthworm species occurrence and richness in five land use systems (LUS) in the southern part of the Campos Gerais in Lapa county. Earthworms were handsorted from up to 18 soil monoliths on five occasions over three years (Feb. 2014, Feb., Mar., Nov. 2015, Jul. 2016) in the following LUS: old native forest, native grassland, young regenerating forest and grass lawn in the Uru Reserve and annual crop fields (soybean) in neighboring private farms (not all systems were sampled on all occasions). Nine earthworm species belonging to four families and five genera were found, of which six were native and three exotic species (Dichogaster gracilis, Amynthas gracilis, A. corticis). Of the native species, Urobenus brasiliensis and Andiorrhinus duseni (a large bodied-worm) are already well known from S and SE Brazil, while the remaining four were new species that require further description (Fimoscolex n.sp.1 and n.sp.2, Glossoscolex n.sp.1 and n.sp.2). In general, more species were found in February (summer) than March and November. The cropping system (soybean) had the lowest abundance and species richness in relation to other sites, although in the young and old forests no earthworms were found on some sample dates. Given the several new species found in this small reserve, and the relatively few sites studied thus far in the Campos Gerais, further efforts are needed to adequately characterize the earthworm fauna of the region, from which many other species are expected.

New species-group taxa of Glossoscolex (Clitellata: Glossoscolecidae) from Rio Grande do Sul, Brazil.

Five new species-group taxa of Clitellata of the genus Glossoscolex from Rio Grande do Sul State, Brazil are described in this paper: Glossoscolex (Glossoscolex) riograndensis n. sp. has three subspecies, G. (G.) riograndensis riograndensis, G. (G.) riograndensis pollulus n. ssp., G. (G.) riograndensis nativus n. ssp. The two other new species are named G. (G.) pastivus n. sp., and G. (G.) pampas n. sp. All new species are part of the truncatus species group within the subgenus, characterized by the presence of male pores in segment xvii. A single unnamed specimen, also described here, is deemed to belong to a sixth new species-group taxon of the truncatus group. A tabular character comparison of the new taxa and known and morphologically similar species is given. Information on the habitat, such as vegetation cover and soil characteristics, is given as well. G. (G.) r. riograndensis and G. (G.) r. pollulus had an unusual storage of sperm in the nephridia. Histological sections were performed to verify it.

New species of Andiorrhinus Cognetti, 1908 (Oligochaeta: Rhinodrilidae) from Venezuela and Brazil.

Findings pertinent to 11 earthworm species from Venezuela and Brazil are reported. Six of these species are described as new to science, one is re-described and relocated in the genus Andiorrhinus, and new sites of occurrence are reported for four other species. Eight species of oligochaetes were found in the Andes in the state of Mérida, Venezuela: Andiorrhinus (Turedrilus) duranti sp. nov., Andiorrhinus (Meridrilus) timotocuica sp. nov., Andiorrhinus (Meridrilus) torondoy sp. nov., Andiorrhinus (Meridrilus) sp. 1, Andiorrhinus (Quibario) tatuy sp. nov., Andiorrhinus (Meridrilus) kuika (Righi, 1993), Andiorrhinus (Meridrilus) mukuci (Righi, 1993), and Andiorrhinus (Meridrilus) rimeda (Righi & Araujo, 2000). Andiorrhinus (Meridrilus) sp. 1, represented by one specimen only, is possibly a new species. Three other species were collected in Brazil: Andiorrhinus (Amazonidrilus) karinae sp. nov. in the Cerrado bioregion of Mato Grosso state; Andiorrhinus (Amazonidrilus) rodriguezi sp. nov. in the Amazon region in compost, and Andiorrhinus (Amazonidrilus) duseni (Michaelsen, 1918) in the Atlantic Forest, in the states of São Paulo and Paraná, the last species characterized by broad geographical and land use occurrences. The new subgenus Quibario was distinguished by the presence of three pairs of hearts in segments 10, 11, and 12. Keys are also included to differentiate species of subgenera Amazonidrilus and Meridrilus. The implications of these results in the context of ecological interactions, and dispersion of Andiorrhinus species in South America are discussed.

The complete mitochondrial DNA sequence of the pantropical earthworm Pontoscolex corethrurus (Rhinodrilidae, Clitellata): Mitogenome characterization and phylogenetic positioning.

Pontoscolex corethrurus (Müller, 1857) plays an important role in tropical soil ecosystems and has been widely used as an animal model for a large variety of ecological studies in particular due to its common presence and generally high abundance in human-disturbed tropical soils. In this study we describe the complete mitochondrial genome of the peregrine earthworm P. corethrurus. This is the first record of a mitochondrial genome within the Rhinodrilidae family. Its mitochondrial genome is 14 835 bp in length containing 37 genes (13 protein-coding genes (PCG) 2 rRNA genes and 22 tRNA genes). It has the same gene content and structure as in other sequenced earthworms but unusual among invertebrates it hasseveral overlapping open reading frames. All genes are encoded on the same strand. Most of the PCGs use ATG as the start codon except for ND3 which uses GTG as the start codon. The A+T content of the mitochondrial genome is 59.9% (31.8% A 28.1% T 14.6% G and 25.6% for C). The annotated genome sequence has been deposited in GenBank under the accession number KT988053.

New species of the earthworm genus Zapatadrilus (Clitellata, Acanthodrilidae) from northern Mexico.

Three new species of the earthworm genus Zapatadrilus are described from Tamaulipas, Mexico: Zapatadrilus aurelius sp. nov., Zapatadrilus huastecus sp. nov., and Zapatadrilus montezumensis sp. nov. Delimitation of the new species was supported by morphological and molecular (genetic distances) evidence. Diagnostic characters of the three new species include: tubulo-racemose prostates in segments 18 and 20, penial setae absent, typhlosole present and intestine beginning in 17/18. Z. montezumensis sp. nov. is separated by its metandric condition, Z. aurelius sp. nov. by the last hearts in 13 and Z. huastecus sp. nov. by the shape of the spermathecae and patterns of genital markings.

New species of Dichogaster Beddard, 1888 (Clitellata: Benhamiidae) with additional records of earthworms from Guadeloupe (French West Indies).

A survey of the earthworms of Guadeloupe was undertaken to improve knowledge of the diversity of native and introduced earthworms of the island and to evaluate native species for use in vermicomposting. Twenty-eight species were found, 8 introduced, 4 uncertain, and 16 presumed native. The introduced species are Pontoscolex corethrurus, Pontoscolex spiralis, Amynthas rodericensis, Perionyx excavatus, Polypheretima elongata, Dichogaster affinis, Eudrilus eugeniae, and Drawida sp. Juveniles of the genera Righiodrilus, Glossodrilus and Periscolex were found, but one cannot say if they are introduced or not without a confirmed identification. Omodeoscolex divergens was collected in several locations, with variation in color, size and male sexual function suggestive of long residence on the island, but we are counting this as of uncertain status and tentatively placing all in the same species. Late juveniles of a large endogeic species of a heretofore unknown genus of the Rhinodrilidae were found only in the most remote location sampled and are presumed to be native. Seven previously reported native Dichogaster were found. Eight non-recorded species of Dichogaster were found, five represented by single specimens or juveniles, for which we give only a brief precis. The three described here are Dichogaster spolstoni n. sp., Dichogaster caraibensis n. sp.,.and Dichogaster etaspiqui n. sp. These are compared to and differentiated from previously known Dichogaster species of the world and of Guadeloupe.