RESUMO
BACKGROUND: Springtails (Arthropoda, Hexapoda, Collembola) are small arthropods commonly found in soil, litter and other habitats all around the Globe. More than 9,000 species have been described worldwide, but knowledge about their diversity and distribution remains far from complete. Reports of springtail diversity in the Antilles are uneven, some islands are relatively well known, whereas others have not been explored at all. The fauna of Puerto Rico is reasonably well known, but many recent reports are scattered in published literature and unpublished theses. NEW INFORMATION: Here, we present a summary of all springtail species identified from the Bank of Puerto Rico, including unpublished records. As a result, we list 146 species including 43 unnamed, included in 65 genera and 17 families. Most species, 33, belong to Entomobryidae, but this possibly reflects the taxonomic expertise of specialists working in Puerto Rico rather than a real bias in the distribution of higher taxa in the islands. In addition to the new records, the database provides information on the world and local distribution of species listed. The dataset, presented here, is work in progress and will be updated as ongoing taxonomic inventories are completed.
RESUMO
Adult members of tribe Paronellini are characterized by a substantially reduced idiochaetotaxy and as a result chaeta homology determination is often ambiguous. To evaluate previous hypotheses of chaetae homology in adult Trogolaphysa, a complete description of the dorsal chaetotaxy of first instar Trogolaphysa jataca (Wray, 1953b), supplemented with observations on first instar Trogolaphysa paracarpenteri sp. nov., is presented. It is showed that first instar Trogolaphysa carries an almost complete set of dorsal chaetae and that the reduction in adult idiochaetotaxy is secondary. In addition, the organization of primary chaetae in T. jataca points to a closer relationship with genera in subfamily Entomobryinae than to Orchesellinae. Based on chaetae correspondence between first instar and adult T. jataca it is established that the inner median chaetae on adult head corresponds to M1 instead of S1, the mesothorax p3 complex includes chaetae p1-p4, and on the fourth abdominal segment, anterior macrochaeta on column A corresponds to A3, and the secondary bothriotrix corresponds to D3p. In addition, T. relicta (Palacios-Vargas, Ojeda & Christiansen, 1985) is re-described based on a paratype, and 12 new species are described: from Mexico, T. stannardi sp. nov., T. dimorphica sp. nov., T. laterolineata sp. nov., T. marieloiseae sp. nov., T. clarencei sp. nov., T. ocellata sp. nov., T. paracarpenteri sp. nov., T. palaciosi sp. nov., T. octosetosa sp. nov., and T. trioculata sp. nov.; from Jamaica, T. balteata sp. nov.; and from Argentina, T. entreriosensis sp. nov.
Assuntos
Artrópodes/classificação , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Argentina , Artrópodes/anatomia & histologia , Artrópodes/crescimento & desenvolvimento , Tamanho Corporal , Ecossistema , Feminino , Masculino , México , Tamanho do ÓrgãoRESUMO
Species diagnosis in Trogolaphysa has been based, until now, almost exclusively on number of eyes and shape of claws and mucro. Chaetotaxy, a character system important to diagnose species in other genera of scaled Entomobryoidea, has been described only for a few Trogolaphysa species. Here the complete dorsal chaetotaxy of six species of Trogolaphysa is described using the AMS and Szeptycki's systems for head and body, respectively. A morphology-based parsimony analysis was performed to evaluate whether chaetotaxic characters overcome the influence of putatively cave adaptive convergent characters to resolve species level relationships, and to evaluate the evolution of the dorsal macrochaetae of the head. Phylogenetic analysis using only putative cave-adaptive characters support clades of unrelated taxa, but the addition of chaetotaxy overcomes the influence of convergent characters. A phylogeny based on all characters supports a trend towards reduced head macrochaetae number. Head macrochaetae are lost beginning with A3 and followed, in order, by S5, S3 and M3. In addition, a checklist of New World Trogolaphysa is provided and two new species, Trogolaphysa giordanoae sp. n. and Trogolaphysa jacobyi sp. n., are described on the basis of material collected in six caves in southern Belize.
RESUMO
Color pattern was one of the most important characters used to diagnose species in the genus Lepidocyrtus until the introduction of chaetotaxy to Collembola taxonomy. Chaetotaxy confirmed most species diagnoses based only on color patterns, but a number of populations with distinct pigmentation patterns have been found to be identical in all other morphological characters. The absence of individuals showing intermediate color patterns prompted Yoshii to suggest that, despite chaetotaxic identity, populations with distinct color forms represent valid species (implying reproductive isolation and therefore biological species) in what he designated as "color pattern species." In Puerto Rico Lepidocyrtus biphasis, L. dispar, and L. caprilesi show a remarkable variation in pigmentation and as a group include 11 different color forms. Here I present a phylogenetic analysis of the cytochrome oxidase I gene (COI) in 17 species of Lepidocyrtus and Pseudosinella, including 11 species and 10 color forms of Puerto Rican Lepidocyrtus, to test Yoshii's color pattern species concept. The analysis shows large genetic distances between species defined based on morphology alone (morphospecies) and between most color variants within morphospecies. The most often used calibration for the COI molecular clock (2.3% sequence divergence per million years) suggests that morphospecies diverged between 20 and 25 million years before present while color forms within morphospecies diverged between 8 and 19 million years ago. This indicates that changes in climate and sea levels during the Pleistocene were irrelevant to the speciation process in the Puerto Rican Lepidocyrtus. Examination of the genetic variation, phylogenetic relationships, and collection data in light of the biological and phylogenetic species concepts supports the hypothesis that most populations of morphospecies differing only in color pattern are distinct species, thus validating Yoshii's color pattern species concept. As a result it is suggested that morphological characters traditionally used in species diagnoses are very conservative indicators of genetic divergence, that the diversity of springtails has been greatly underestimated, and that studies concerned with identifying factors promoting speciation in Collembola could be misled if they do not include analysis of mitochondrial markers.