Dataset on the isotopic (ẟ13C, ẟ15N) and elemental (C, N) composition of estuarine primary producers in the subtropical Southwestern Atlantic coast

Benthic and pelagic primary producers had their isotopic (ẟ13C, ẟ15N) and elemental (C, N) composition monitored in the Patos Lagoons estuary, in southern Brazil. The present dataset comprises temporal data obtained through seasonal samplings of C3 (Scirpus spp.) and C4 (Spartina densiflora) salt marsh plants, ephemerous bloom-forming drift macroalgae (Ulvophyceae), the widgeon grass Ruppia maritima, particulate (POM) and sedimentary (SOM) organic matter in shallow waters (< 2m) of a subtropical estuary from austral summer 2010 to autumn 2016. POM and SOM were collected as proxies of phytoplankton and microphytobenthos, respectively. Salt marsh plants were randomly sampled (N = 126) at a regularly flooded low marsh area, whereas submerged drift macroalgae (N = 29) and Ruppia plants (N = 14) were collected in adjacent mudflats. POM was collected (N = 33) by filtering water samples using glass fiber filter. SOM was obtained (N = 35) by removing superficial sediment. In laboratory, samples were processed and further analyzed for total organic carbon (TOC), total nitrogen (TN) and carbon (13C/12C) and nitrogen (15N/14N) stable isotopes ratios. With a total of 237 samples analyzed, this dataset provides key information on the isotopic and elemental composition of distinct estuarine primary producers and sources of particulate organic matter (POM and SOM) and their temporal variability in a highly variable aquatic environment. Such knowledge may add to ecological studies investigating food webs, biogeochemical cycles and sources tracking in coastal systems.

CHECKLIST OF HIGHER AQUATIC PLANTS OF OMSK REGION

The article presents the results of generalizing the factual material on the diversity of hydromacrophytes from the divisions Marchantiophyta, Bryophyta and Magnoliophyta in the territory of the Omsk region. For each species the geographical frequency of occurrence in natural zones, the group of halobility and trophicity are indicated. For the region 176 species of higher hydromacrophytes have been identified. The division Magnoliophyta is distinguished by the greatest species diversity, which includes 116 species (65.9% of all higher hydromacrophytes), the division Bryophyta accounts for 49 species (27.9%), Marchantiophyta – 7 (4.0%), the divisions Equisetophyta and Polypodiophyta include only 2 species each (1.1%). Currently in the region 24 species of higher hydromacrophytes are included in the number of protected species with an established category of protection or as species that need special attention to their state and natural environment. In total, the following moss species are known from several habitats: Riccia fluitans, R. frostii, R. rhenana, Ricciocarpos natans, Fissidens adianthoides, Paludella squarrosa and vascular plants: Ceratophyllum platyacanthum subsp. oryzetorum, Elatine hydropiper, Veronica beccabunga, Najas marina, Sagittaria trifolia, Potamogeton rutilus, including brackish Ruppia maritima, Althenia orientalis, Zannichellia palustris var. repens.

New find of rare freshwater brown algae Pleurocladia lacustris А.Braun (Phaeophyсеае) from Dnieper Estuary of the Black Sea (Ukraine)

In article reports a new find of Pleurocladia lacustris in Ukraine. The species grew in the brackish-water Dnieper Estuary (depth 0.2 m, salinity of estuary water was 4.68‰, temperature – 23 °С, pH – 7.9) P. lacustris is a filamentous benthic species, the cells of which are not calcified here, as in freshwater conditions, but are covered with a slimy sheath. It was found in fouling of bushes of green algae Cladophora glomerata (Linnaeus) Kützing and Ulva flexuosa Wulfen, as well as blue-green (Calothrix C.Agardh ex Bornet & Flahault and Oscillatoria sp.) on a concrete slab in July 2020. The thickets of Potamogeton perfoliatus L., Ruppia maritima L., and Stuckenia pectinata (L.) Börner predominated in the coastal area of the estuary. Color illustrations of the vegetative and generative organs of P. lacustris are presented, its diagnostic macroscopic and microscopic characteristics are shown, which turned out to be somewhat larger than the data of the determinants. The ecological characteristics of the algae habitat meet the known requirements. This rare species is known in about 50 localities in Europe, North America, Australia and Africa. In many countries P. lacustris is considered an endangered species and is included in the protected red lists.

A profound view and discourse on the typification and status of three confused taxa: Ruppia maritima, R. spiralis and R. cirrhosa

Taxonomic difficulties have persisted within the genus Ruppia for a long time. We first unravel misconceptions as perceived on different continents and subsequently present a revised interpretation of the identity and typification of three European taxa at species level: Ruppia maritima L., Ruppia spiralis L. ex Dumortier, and Ruppia cirrhosa (Petagna) Grande. To do this, historical specimens, illustrations and original descriptions were studied. We supersede a previous choice of the figure of Buccaferrea maritima, foliis minus acutis Micheli (1729) as the lectotype of R. maritima and type species of the genus Ruppia owing to a serious conflict with the protologue. Based on a meticulous interpretation of protologues and figures in a historical context, we reject the recent view of assigning R. cirrhosa and its proposed lectotype (iconotype) as a homotypic synonym of R. maritima. We agree with an earlier lectotypification of R. spiralis, though for another reason than the above-mentioned abused homotypy. Consequently, R. cirrhosa is a synonym of neither R. maritima or R. spiralis, based on material from Petagna in the Herbarium of Naples designated as the holotype of R. cirrhosa. We argue for three species to be considered as fully independent taxa: R. maritima, R. spiralis and R. cirrhosa.

Flora do Rio de Janeiro: Ruppiaceae

Resumo O presente estudo apresenta a flora de Ruppiaceae no estado do Rio de Janeiro. O trabalho tem por base a análise morfológica de materiais depositados em herbários e coletas de campo, além de dados da literatura. Foi registrada uma espécie: Ruppia maritima. Descrições, ilustrações, dados sobre habitat e distribuição geográfica são apresentados.

Ecology and distribution patterns of Chara connivens (Charophyta, Characeae) on the Canary Islands – the first record from Fuerteventura

The paper presents the first record of a Chara connivens (Characeae) stand from Fuerteventura (Canary Islands, Spain). The species was previously recorded only on Tenerife and Lanzarote, mostly in marine and artificial habitats. Physicochemical parameters of water and morphological features of the thalli and plant community were analyzed. General habitat requirements of C. connivens populations located in Europe, North Africa, and South-West Asia were reviewed. The newly described stand was located in a natural rock crevice that was part of a riverbed in El Barranco de las Peñitas (Penitas Canyon). This habitat was unshaded and filled with brackish water. C. connivens co-occurred with Cladophora glomerata and Ruppia maritima. Our report on the presence of C. connivens in the Spanish territory of the Atlantic Ocean is the first in almost 40 years. The distribution of C. connivens and its plant associations on the Canary Archipelago are poorly explored, which is why this topic requires further research.