Seabirds and seals as drivers of plant succession on Surtsey

Plant colonization and succession on Surtsey have been monitored since 1965. In 2019, the 75th species of vascular plants was detected on the island, 62 species were present and about 40 species had established viable populations. Over the last decade colonization has slowed down and the number of present species not increased. The rising number of seagulls breeding on the island after 1985 had a great impact on plant colonization and vegetation development. While most parts of the island remained barren, a grassland area (13 ha in 2018) developed in the main seagull breeding colony on the southern part of the island. This development is attributed to transfer of nutrients from sea to land by the seagulls. In recent years a dense patch of vegetation, 2 ha in 2018, has also developed on the low, northern spit of the island, where a few pairs of seagulls breed in the spring and grey seals haul out and breed in the fall in considerable numbers. In a survey conducted during the grey seal pupping period in 2019, the seal abundance and spatial distribution was mapped accurately for the first time. The results show that the dense vegetation of the spit and seal distribution are clearly overlapping. The continuous shrinking of the island and its spit has led to an increasing concentration of the seals in their breeding area. Based on a literature survey we estimated the nitrogen (N) input from sea to land by the grey seals as 9-13 kg N/ha in 2019. This compares to an estimated input of 5-30 kg N/ha/yr by the seagulls breeding in the same area during 2015-2019. Within the grey seal and seagull breeding area on the spit of the island, a distinct community of shore plants has developed. Measurements of plant cover and biomass in permanent plots on Surtsey in 2018 and 2019 show that development on part of the spit is reaching a similar state as in the old gull colony on the southern part of the island. This suggests that the grey seals along with the seagulls are important drivers of plant succession on the northern spit. Further research on the effects of the seals on nutrient transfer from sea to land and ecosystem development on Surtsey is recommended.

Physoglossus: A new ground beetle genus of the enigmatic tribe Physocrotaphini Chaudoir, 1862 (Carabidae: Anthiinae) from the Western Ghats, a global hotspot of Biodiversity in south west India

A new genus of enigmatic tribe Physocrotaphini, Physoglossus gen. nov., with a new species Ph. devagiriensis sp. nov. from a dry deciduous forest in the rain shadow belt of the south Western Ghats in south west India is described. Presence of mentum with bifid median tooth and large oval depression with dense patch of filamentous setae on 2nd and 3rd male sternites makes it intermediate to the Physocrotaphini genera, Pogonoglossus, Foveocrotaphus and Physocrotaphus. Key words: new ground beetle species, Anthiinae, the Western Ghats, India

A study of distilled water and zamzam water as dielecric dense patch antenna at 5 GHz

<p>This paper was performed in order to study about distilled water and zamzam water which act as dielectric dense (DD) patch antenna at 5 Ghz applications. This antenna is proposed and designed using FR-4 substrate that sandwiched together to perform DD structure. The proposed antennas employ simple rectangular structure that fed with inset feeder surround by electromagnetic bandgap (EBG) structure.In order too enhance the gain, superstrate is applied on top of the antenna. This antenna offers a wideband return loss of more than -10dB between 4.41-5.52Ghz (around 22.2%) which can be applied in 5 Ghz applications. Details of DD water antenna of center frequency for 5 Ghz is presented and discussed.</p>

Sponge grade body fossil with cellular resolution dating 60 Myr before the Cambrian

An extraordinarily well preserved, 600-million-year (Myr)-old, three-dimensionally phosphatized fossil displaying multiple independent characters of modern adult sponges has been analyzed by SEM and synchrotron X-ray tomography. The fossilized animal (Eocyathispongia qiania gen. et sp. nov.) is slightly more than 1.2 mm wide and 1.1 mm tall, is composed of hundreds of thousands of cells, and has a gross structure consisting of three adjacent hollow tubes sharing a common base. The main tube is crowned with a large open funnel, and the others end in osculum-like openings to the exterior. The external surface is densely covered with flat tile-like cells closely resembling sponge pinacocytes, and this layer is punctuated with smaller pores. A dense patch of external structures that display the form of a lawn of sponge papillae has also survived. Within the main funnel, an area where features of the inner surface are preserved displays a regular pattern of uniform pits. Many of them are surrounded individually by distinct collars, mounted in a supporting reticulum. The possibility cannot be excluded that these pits are the remains of a field of choanocytes. The character set evinced by this specimen, ranging from general anatomy to cell type, uniquely indicates that this specimen is a fossil of probable poriferan affinity. So far, we have only this single specimen, and although its organized and complex cellular structure precludes any reasonable interpretation that its origin is abiogenic, confirmation that it is indeed a fossilized sponge will clearly require discovery of additional specimens.

Eyespot and other pigments in nematode esophageal muscle cells

Nematode eyespots are recognizable as paired spots of granular, dense pigment localized within anterior muscle cells of the esophagus, or projections thereof. The 10 species studied here include a variety of morphologies and colors. A third, less dense, patch of eyespot pigment was observed in six of the species. Of the species for which eggs could be obtained, eyespots of five developed 2–5 days prior to larval hatching, but those of one, Symplocostoma sp., appeared only in males just prior to the last moult. Chemical properties and absorption spectra of eyespot pigments of the more common species were investigated. The brown eyespot pigment of Enoplus spp. resembles mature eumelanin, and the purplish pigment of two other species is probably incompletely polymerized eumelanin. Properties of less stable, reddish eyespot of four species are unlike melanins or other known pigment classes.Another granular esophageal pigment was observed in 4 of the 10 species. Unlike eyespot pigment it is distributed along the length of the esophagus and is absent at hatching, accumulating with age. That of Enoplus spp. resembles hemosiderin in chemical properties. Also, hemoglobin was identified in nonpigmented regions of the esophageal muscle and in the hypodermal chords of two species.