Development of the ear, hearing capabilities and laterophysic connection in the spotfin butterflyfish (Chaetodon ocellatus)

The ontogeny of the ear, swim bladder and laterophysic connection was investigated in the spotfin butterflyfish, Chaetodon ocellatus in order to determine how the development of the laterophysic connection (a Chaetodon synapomorphy) is correlated with ontogenetic changes in the hearing capabilities in these abundant and ecologically important coral reef fishes. Histological and cleared and stained material revealed that the medial opening in the lateral line canal in the supracleithrum (which defines the laterophysic connection), an inflated physoclistous swim bladder, and the three otolithic organs are already present in the smallest individuals examined (7?C15?mm SL). The medial opening in the supracleithrum increases in size and the cylindrical swim bladder horns form after the loss of the head plates characteristic of the tholichthys stage, in individuals ??29?mm SL. The three sensory maculae of the ear increase in size, and the shape of the sacculus changes most dramatically with fish growth; hair cell density is highest in the utriculus. Physiological analysis of the reponse to sound pressure showed that larval and juvenile C. ocellatus had a hearing sensitivity peak at 100?C200?Hz, which was ~30?C40?dB more sensitive than that measured in larval coral reef fishes (e.g., damselfishes) that lack swim bladder horns. C. ocellatus did not show any ontogenetic changes in sensitivity to sound pressure, which may be explained by the fact that the growth of the swim bladder horns maintains the small distance between the swim bladder and ear that was established earlier during the larval stage. The timing of the development of the swim bladder horns suggests that if the laterophysic connection has a sensory acoustic function, its presence in individuals >29?mm SL suggests that its role is limited to post-settlement, reef-based behaviors.     

Effects of intensive human management on the taxonomic and functional diversity of ground beetles in a planted forest landscape

The rapid expansion of planted forests harms native biodiversity. Few studies report the effects of replacing wetlands with planted forests on ground beetles. We analyze how the taxonomic and functional diversity of ground beetles are affected by intensive management of a planted forest landscape in the Lower Delta of the Parana River. We defined six habitat types (n?=?3, N?=?18): young and mature willow (YW, MW), young and mature poplar without cattle (YP, MP), young and mature silvopastoral poplar (YS, MS). Using pitfall traps (N?=?1728), we recorded 35 species (1896 individuals). YW and MS reached the highest taxonomic diversity and richness. YW with more vertical heterogeneity showed higher species richness than MW. Hydrophilic species were more abundant in YW. Zoophagous species were more abundant in MS. YS, MS, and YW reached the highest functional evenness, which implies that a large part of the functional niches was used. Cattle dung and freshwater canals for livestock offer more resources for ground beetles. The planted tree species, stand age, and presence of cattle affects taxonomic and functional diversity of ground beetles. Willow and silvopastoral planted forests are the most suitable habitats for hosting wetland species. So, we recommend using willow species rather than poplar species when planted forests replace fluvial wetlands, increasing irrigation of poplar planted forests through ditches and canals, conserving or restoring different strata of understory to increase vertical heterogeneity, and maintaining the landscape heterogeneity. These management measures are essential to prevent the loss of wetland species and conserve ground beetle’s diversity.

     

A new species of Notodiaptomus Kiefer, 1936 (Copepoda,Diaptomidae) from the Amazon and Orinoco River Basins

A new species of Notodiaptomus, Notodiaptomus simillimus sp. nov., based on the female originally but erroneously assigned to Rhacodiaptomus calatus, and the corresponding newly discovered male, is described and illustrated in detail. The designation of the female as a new species of Notodiaptomus, and the recognition of the corresponding new male, is based on detailed morphological and biometrical studies, analysis of the known distribution and material from laboratory cultures. Morphological analysis demonstrated that the female shares the form of the external genital area and setal armature of the exopod 2 of leg 5 with other species of Notodiaptomus but they differ from those exhibited by species of Rhacodiaptomus. The distributions of the female and male assigned to Notodiaptomus simillimus sp. nov. overlap and include the Atabapo and Guaviare Rivers and Lago Calado. On the other hand, the distributions of the males and females originally assigned to R. calatus are disjunct and where they overlap, that is, in Lago Calado, each is accompanied by its respective mate. Laboratory cultures showed that, as expected, copulation did not occur between males and females described originally as R. calatus. This experiment demonstrated the existence of reproductive isolating mechanisms between these females and males, and confirmed the existence of two distinct genetic pools, i.e. two different species, the original males being of the valid R. calatus and the female a new Notodiaptomus. This female and the corresponding newly discovered male are N. simillimus. The new species is closely related to N. coniferoides.     

A remarkable new genus and a new species of chewing louse (Phthiraptera,Ischnocera, Philopteridae) from Brazil

A new genus of chewing louse as Bobdalgleishia, and its type species Bobdalgleishia stephanophallus sp. n. (Phthiraptera) belonging to the Brueelia-complex (Ischnocera: Philopteridae) are described. Adults of the new species are fully described, illustrated and compared morphologically with the type species of Motmotnirmus Mey & Barker, 2014, which is its closest relative. The type host of Bobdalgleishia stephanophallus is a subspecies of the great jacamar Jacamerops aureus ridgwayi Todd, 1943, an endemic Amazonian bird distributed in northern Brazil, and the type locality is the State of Pará. Bobdalgleishia is a remarkable genus with unique morphological and chaetotaxic characters which readily separate it from other members of the Brueelia-complex, in particular by having the first two marginal temporal and ocular setae very long.     

Importance of the genital operculum in the taxonomy of South American Diaptomidae (Copepoda,Calanoida)

For the first time, the structures of the female genital field are described and compared among ten species of Venezuelan diaptomids. A nomenclature for these structures is suggested, and there is a preliminary report on the interspecific differences observed in one of these structures, the genital operculum.     

First records of <Emphasis Type="Italic">Trichodectes canis</Emphasis> (Insecta: Phthiraptera: Trichodectidae) from Darwin’s fox, <Emphasis Type="Italic">Pseudalopex fulvipes</Emphasis> (Mammalia: Carnivora: Canidae)

The presence of the dog biting louse, Trichodectes canis (De Geer, 1778; Ischnocera: Trichodectidae), is reported for the first time in the critically endangered Pseudalopex fulvipes (Martin, 1837) in Chiloé Island, south Chile.