The Myriapoda of Halimun-Salak National Park (Java, Indonesia): overview and faunal composition

DNA barcoding data release for the Phoridae (Insecta, Diptera) of the Halimun-Salak National Park (Java, Indonesia)

Launched in 2015, the large-scale initiative Indonesian Biodiversity Discovery and Information System (IndoBioSys) is a multidisciplinary German-Indonesian collaboration with the main goal of establishing a standardised framework for species discovery and all associated steps. One aspect of the project includes the application of DNA barcoding for species identification and biodiversity assessments. In this framework, we conducted a large-scale assessment of the insect fauna of the Mount Halimun-Salak National Park which is one of the largest tropical rain-forest ecosystems left in West Java. In this study, we present the results of processing 5,034 specimens of Phoridae (scuttle flies) via DNA barcoding. Despite limited sequencing success, we obtained more than 500 clusters using different algorithms (RESL, ASAP, SpeciesIdentifier). Moreover, Chao statistics indicated that we drastically undersampled all trap sites, implying that the true diversity of Phoridae is, in fact, much higher. With this data release, we hope to shed some light on the hidden diversity of this megadiverse group of flies.

Madagascarhinus, a new genus of the family Siphonorhinidae with two new species from Madagascar (Diplopoda, Siphonophorida)

Millipedes of the family Siphonorhinidae Cook, 1895, famous for including the leggiest animal on this planet until recently, with up to 750 legs, show a disjunct distribution in California, South Africa and South-East Asia (from India to the Indonesian Islands of Java and Flores). Here I formally describe the first members of the family from Madagascar, Madagascarhinus madagascariensis n. gen., n. sp. and Madagascarhinus andasibensis n. gen., n. sp., from degraded central highland rainforests. Both species of Madagascarhinus n. gen. are relatively short (61 or 63 tergites), setose, pale and slender, and differ from the other known five genera of the family in numerous characters of the antennae, head, and tergites.

A previously unknown feeding mode in millipedes and the convergence of fluid feeding across arthropods

We report fluid feeding with a sucking pump in the arthropod class Diplopoda, using a combination of synchrotron tomography, histology, electron microscopy, and three-dimensional reconstructions. Within the head of nine species of the enigmatic Colobognatha, we found a pumping chamber, which acts as positive displacement pump and is notably similar to that of insects, showing even fine structural convergences. The sucking pump of these millipedes works together with protractible mouthparts and externally secreted saliva for the acquisition of liquid food. Fluid feeding is one of the great evolutionary innovations of terrestrial arthropods, and our study suggests that it evolved with similar biomechanical solutions convergent across all major arthropod taxa. While fluid-feeding insects are megadiverse today, it remains unclear why other lineages, such as Colobognatha, are comparably species poor.

Reinvestigating the phylogeny of Myriapoda with more extensive taxon sampling and novel genetic perspective

Background

There have been extensive debates on the interrelationships among the four major classes of Myriapoda-Chilopoda, Symphyla, Diplopoda, and Pauropoda. The core controversy is the position of Pauropoda; that is, whether it should be grouped with Symphyla or Diplopoda as a sister group. Two recent phylogenomic studies separately investigated transcriptomic data from 14 and 29 Myriapoda species covering all four groups along with outgroups, and proposed two different topologies of phylogenetic relationships.

Methods

Building on these studies, we extended the taxon sampling by investigating 39 myriapods and integrating the previously available data with three new transcriptomic datasets generated in this study. Our analyses present the phylogenetic relationships among the four major classes of Myriapoda with a more abundant taxon sampling and provide a new perspective to investigate the above-mentioned question, where visual genes' identification were conducted. We compared the appearance pattern of genes, grouping them according to their classes and the visual pathways involved. Positive selection was detected for all identified visual genes between every pair of 39 myriapods, and 14 genes showed positive selection among 27 pairs.

Results

From the results of phylogenomic analyses, we propose that Symphyla is a sister group of Pauropoda. This stance has also received strong support from tree inference and topology tests.

Description of the first species of Glomeridesmida from Thailand (Diplopoda, Glomeridesmida, Glomeridesmidae)

With three genera and 35 previously known species from India, SE Asia, Central and South America, Glomeridesmida are one of the least diverse Diplopoda groups. Here we describe Glomeridesmussiamensissp. nov., the first species of the order Glomeridesmida from Thailand. The geographically nearest confamiliar species have been described from southern India, Sumatra and Java. The species is described combining photographs, light- and scanning electron microscopy of mature and younger males, females and juveniles. Several characters are illustrated for the first time for an Asian representative of the family Glomeridesmidae. In addition to the type locality of G.siamensissp. nov. from Krabi province, locality data of unidentified Glomeridesmus from Thailand are also given. These data are providing further evidence that the Glomeridesmida are not uncommon, but overlooked as they are small and difficult to collect. The unusual telopods and other morphological characters of G.siamensissp. nov. differ considerably from the few Glomeridesmus males described from Central and South America as well as from India, but the unclear status of two generic names available for species from Indonesia prevents us from adding another generic name to this small and understudied order.