A new species of pygmy Paroctopus (Cephalopoda: Octopodidae): the smallest southwestern Atlantic octopod, found in sea debris

The new species, Paroctopus cthulu sp. nov. Leite, Haimovici, Lima and Lima, was recorded from very shallow coastal waters on sandy/muddy and shelter-poor bottoms with natural and human-origin debris. It is a small octopus, adults are less than 35 mm mantle length (ML) and weigh around 15 g. It has short to medium sized arms, enlarged suckers on the arms of both males and females, large posterior salivary glands (25 %ML), a relatively large beak (9 % ML) and medium to large mature eggs (3.5 to > 9 mm). The characteristics of hatchlings of two brooding females, some of their anatomical features, and in-situ observations of their behaviour are a clue to the life history of it and closely related pygmy octopuses. The Bayesian phylogenetic analysis showed that Paroctopus cthulu sp.nov. specimens grouped in a well-supported clade of Paroctopus species, separate from P.joubini and P. cf mercatoris from the Northwestern Atlantic . The description of this new species, living in a novel habitat of human debris in shallow water off Brazil, offered an opportunity not only to evaluate the relationship among the small octopuses of the western Atlantic, Caribbean and eastern Pacific, but also their adaptation to the Anthropocene period.

Telmatoblechnum (Blechnaceae): a new genus for the Uruguayan flora

Telmatoblechnum, with the species Telmatoblechnum serrulatum (Blechnaceae), is recorded for the first time for the Uruguayan flora. The species, so far known from southern Brazil and Northeastern Argentina as its southernmost distribution limit, was collected for the first time in crevices between rocks of basalt and sandstone in a small hill in Uruguay (Rivera). Its morphological characteristics and the novel habitat for the species are included; photographs, a map with the location of the new record, as well as a key to the genera of Blechnaceae in Uruguay are provided.

The first register of the weed fern Pteris cretica var. laeta (Pteridaceae) in central Argentina

Pteris cretica L. var. laeta is recorded for the first time in the Comechingones biogeographic province in central Argentina. This is the first record of P. cretica in central Argentina, and P. cretica var. laeta for the country. Until now Pteris cretica has only been known to occur, in America, in North America (Florida), Central America and South America in Neotropical biomes from Peru, Chile, Brazil, Paraguay, Uruguay and northern Argentina as established in the Yungas biogeographic province, and as ruderal in Buenos Aires. An updated description is provided, along with pictures, differences with P. cretica var. cretica, and characteristic of the novel habitat of the species.

Snow Algae Blooming Are Benefitable for Microinvertebrates Assemblages (Tardigrada and Rotifera) on the Seasonal Snow Patches in Japan

Although studies on snow algae and macroinvertebrates have been frequently conducted on snow patches, no attention have been paid to ubiquitous microinvertebrates which in other cold habitats reach high biomass and play various trophic roles. The aim of this study was to search microinvertebrates in seasonal snow patches in Mt. Gassan, in northern Japan, and identify factors determining their distribution associated with snow algal blooming of various coloration (red, green, and yellow). Microscopic observation revealed presence of two major groups of microinvertebrates Tardigrada and Rotifera. Tardigrades and rotifers were the most abundant and frequent in green snow formed by blooming of Chloromonas sp., but few in red or yellow snow. Body length of tardigrades increased through the melting season and animals laid eggs on colored snow. These results suggest tardigrades successfully grew and reproduced on snow patches. Taking into account the presence of tardigrades and rotifers mostly in green snow (only few found in red and yellow) with high densities, we may assume green snow patches constitute important and unique low-temperature ecosystems for microinvertebrates in a temperate mountainous forest. Area of snow algae blooming worldwide are unrecognized novel habitat for tardigrades and rotifers.