Revision of the New Caledonian endemic genus Gracilipsodes (Trichoptera: Leptoceridae: Grumichellini)

The taxonomy and systematics of the New Caledonian endemic caddisfly genus Gracilipsodes Sykora, 1967 (Trichoptera: Leptoceridae: Grumichellini) are reviewed. Seven new species represented by males are described and illustrated: Gracilipsodes aoupiniensis sp. nov. , Gracilipsodes aureus sp. nov. , Gracilipsodes aurorus sp. nov. , Gracilipsodes grandis sp. nov. , Gracilipsodes koghiensis sp. nov. , Gracilipsodes lanceolatus sp. nov. , and Gracilipsodes robustus sp. nov. Molecular phylogenetic analyses are applied to discern the relationships among the species of the genus and their closest relatives, based on sequence characters from the nuclear gene translation elongation factor-1α (EF-1α) and the three mitochondrial genes cytochrome oxidase I (COI), COII, and ribosomal large subunit (16S). The data are analyzed using parsimony and Bayesian inference, revealing a monophyletic Gracilipsodes with the eastern Australian monotypic genus Triplexa as its closest relative. Gracilipsodes is in turn divided into two major lineages.  © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 153 , 425–452.     

The evolutionary history of Trichoptera (Insecta): A case of successful adaptation to life in freshwater

The insect order Trichoptera (caddisflies) forms the second most species‐rich monophyletic group of animals in freshwater. So far, several attempts have been made to elucidate its evolutionary history with both morphological and molecular data. However, none have attempted to analyse the time frame for its diversification. The order is divided into three suborders – Annulipalpia, Integripalpia and ‘Spicipalpia’. Historically, the most problematic taxon to place within the order is ‘Spicipalpia’, whose larvae do not build traditional cases or filtering nets like the majority of the caddisflies. They have previously been proposed to be the sister group of all other Trichoptera or more advanced within the order, with equivocal monophyly and with different interordinal placements among various studies. In order to resolve the evolutionary history of the caddisflies as well as timing their diversification, we utilized fragments of three nuclear (carbamoylphosphate synthethase, isocitrate dehydrogenase and RNA polymerase II) and one mitochondrial (cytochrome oxidase I) protein coding genes, with 16 fossil trichopteran taxa used for time calibration. The ‘spicipalpian’ families are recovered as ancestral to all other caddisflies, though paraphyletic. We recover stable relationships among most families and superfamilies, resolving many previously unrecognized phylogenetic affinities amongst extant families. The origin of Trichoptera is estimated to be around 234 Ma, i.e. Middle – Late Triassic.     

Molecular phylogeny of Sericostomatoidea (Trichoptera) with the establishment of three new families

We inferred the phylogenetic relationships among 58 genera of Sericostomatoidea, representing all previously accepted families as well as genera that were not placed in established families. The analyses were based on five fragments of the protein coding genes carbamoylphosphate synthetase (CPSase of CAD), isocitrate dehydrogenase (IDH), Elongation factor 1a (EF‐1a), RNA polymerase II (POL II) and cytochrome oxidase I (COI). The data set was analysed using Bayesian methods with a mixed model, raxml , and parsimony. The various methods generated slightly different results regarding relationships among families, but the shared results comprise support for: (i) a monophyletic Sericostomatoidea; (ii) a paraphyletic Parasericostoma due to inclusion of Myotrichia murina, leading to synonymization of Myotrichia with Parasericostoma; (iii) a polyphyletic Sericostomatidae, which is divided into two families, Sericostomatidae sensu stricto and Parasericostomatidae fam.n. ; (iv) a polyphyletic Helicophidae which is divided into Helicophidae sensu stricto and Heloccabucidae fam.n. ; (v) hypothesized phylogenetic placement of the former incerta sedis genera Ngoya, Seselpsyche and Karomana; (vi) a paraphyletic Costora (Conoesucidae) that should be divided into several genera after more careful examination of morphological data; (vii) reinstatement of Gyrocarisa as a valid genus within Petrothrincidae. A third family, Ceylanopsychidae fam.n. , is established based on morphological characters alone. A hypothesis of the relationship among 14 of the 15 families in the superfamily is presented. A key to the families is presented based on adults (males). Taxonomic history, diagnosis, habitat preference and distribution data for all sericostomatoid families are presented. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:CF6A6B9F‐6A72‐4265‐BD09‐3A710DFCD7B1 .     

Description of Notoernodes stoltzei sp. nov. (Trichoptera: Beraeidae), and of the larva of the genus

Notoernodes stoltzei sp. nov. is described from the Uzungwa Mountains in Tanzania based on pharate males and larvae. The previously unknown larval stage of the genus is also described. A revised diagnosis to Notoernodes is presented.     

Long-term exposure to enhanced ultraviolet-B radiation in the sub-arctic does not cause oxidative stress in Vaccinium myrtillus

The aim of this work was to assess whether or not oxidative stress had developed in a dwarf shrub bilberry ( Vaccinium myrtillus L.) under long-term exposure to enhanced levels of ultraviolet-B (u.v.-B) radiation. The bilberry plants were exposed to increased u.v.-B representing a 15% stratospheric ozone depletion for seven full growing seasons (1991–1997) at Abisko, Swedish Lapland (68°N). The oxidative stress was assessed on leaves and stems by analysing ascorbate and glutathione concentrations, and activities of the closely related enzymes ascorbate peroxidase (EC 1.11.1.11) and glutathione reductase (EC 1.6.4.2). The affects of autumnal leaf senescence and stem cold hardening on these variables were also considered. The results showed that the treatment caused scarcely any response in the studied variables, indicating that u.v.-B flux representing a 15% ozone depletion under clear sky conditions is not sufficient to cause oxidative stress in the bilberry. It is suggested that no strain was evoked since adaptation was possible under such u.v.-B increases. The studied variables did, however, respond significantly to leaf senescence and especially to stem cold hardening.     

The diversity and radiation of the largest monophyletic animal group on New Caledonia (Trichoptera: Ecnomidae: Agmina)

In area, New Caledonia is the smallest of the world’s 25 official biodiversity hotspots, but in many taxonomic groups, the island has the highest concentration of species on earth, particularly so in the freshwater insect order Trichoptera. This study aims at applying molecular data and morphology for estimating the real species diversity of the genus Agmina on New Caledonia and investigating potential effects of ultramafic rock substrate on diversification. A dated molecular phylogeny was applied to study diversity and diversification related to geological substrate using the dispersal–extinction–cladogenesis model, diva and Bayesian ancestral character reconstruction. More than 47 species (> 63%) were unknown to science. Initial radiation occurred on ultramafic substrate followed by several independent dispersal events to nonultramafic substrate. The rate of shift from ultramafic to nonultramafic substrate was significantly higher than the rate of shift in the opposite direction, indicating a possible cost associated with living on ultramafic substrate.     

Association and description of males, females and larvae of two New Caledonian Xanthochorema species (Trichoptera: Hydrobiosidae) based on mitochondrial 16S and COI sequences

A method for associating larvae, females and males of Trichoptera is demonstrated for New Caledonian Hydrobiosidae species of the genus Xanthochorema, using cytochrome oxidase subunit I (COI) and 16S mitochondrial gene sequences. Two species, X. caledon Kimmins, 1953 and X. celadon Schmid, 1989 , previously with unknown larvae and undescribed females, were associated, and males, females and larvae of both species are described. Mitochondrial COI and 16S gene fragments are demonstrated to be useful for association of sexes and life stages of the two species, and distance measures show that the method is likely to also be useful for other species within the genus. The associations are well supported by high bootstrap and jackknife values.     

Homology of fin lepidotrichia in osteichthyan fishes

Lepidotrichia are dermal elements located at the distal margin of osteichthyan fins. In sarcopterygians and actinopterygians, the term has been used to denote the most distal bony hemisegments and also the more proximal, scale-covered segments which overlie endochondral bones of the fin. In certain sarcopterygian fishes, including the Rhizodontida, these more proximal, basal segments are very long, extending at least half the length of the fin. The basal segments have a subcircular cross section, rather than the crescentic cross section of the distal lepidotrichial hemisegments, which lack a scale cover and comprise short, generally regular, elements. In rhizodonts and other sarcopterygians, e.g. Eusthenopteron, the basal elements are the first to appear during fin development, followed by the endochondral bones and then the distal lepidotrichia. This sequence contradicts the 'clock-face model' of fin development proposed by Thorogood in which the formation of endochondral bones is followed by development of lepidotrichia. However, if elongate basal 'lepidotrichia' are not homologous with more distal, jointed lepidotrichia and if the latter form within a distal fin-fold and the former outside this fold, then Thorogood's 'clock-face' model remains valid. This interpretation might indicate that the fin-fold has been lost in early digited stem-tetrapods such as Acanthostega and Ichthyostega and elongate basal elements, but not true lepidotrichia, occur in the caudal fins of these taxa.     

The Effect of Sodium and Calcium on the Translocation of 14C-sucrose in Excised Cotton Roots

The effect of sodium and calcium on the translocation of ¹⁴C-sucrose in excised cotton roots (Gossypium birsutum) was studied. The roots were allowed to elongate in a modified Guinn's medium that was very low in calcium (6.25 × 10^?2 mM) and sodium (8.70 × 10^?3 mM). After a period of six days the roots were transferred to 20 × 100 mm Petri dishes that contained 10 × 40 mm Petri dishes as center wells. The roots were draped over the edge of the center well and extended into the outer dish. The outer Petri dish and its center well contained the same solution except that sucrose was supplied only in the center well. The sucrose used was spiked with uniformally labeled ¹⁴C-sucrose. Four treatments were started which varied in their Na and Ca content. Three and six day harvests were taken and the amount of ¹⁴C that had moved from the distal (in the center well) to the apical root section (in the outer dish) was determined. Increasing substrate Na or Ca caused an increase in ¹⁴C-sucrose translocation and the effects of both ions were additive by the final harvest. These results were found to be independent of treatment effects on growth and respiration of the excised roots. These data support the conclusion that Na may partially substitute for Ca in carbohydrate translocation. Thus, roots supplied the Low Ca-High Na and High Ca-Low Na treatments had equal translocation rates over a six day period. The highest translocation rate was obtained with the High Ca-High Na treatment. Data from the High Ca-High Na treatment on two successive three day periods indicate that Na may have a role in translocation other than that associated with substitution for Ca, or maintenance of tissue hydration.