On Thaicypris panhai gen. et sp. nov., a new herpetocypridine ostracod (Crustacea: Ostracoda: Cyprididae) from Thailand

A new genus, Thaicypris gen. nov., in the tribe Herpetocypridini Kaufmann, 1900 of the subfamily Herpetocypridinae Kaufmann, 1900 is established to accommodate a new species from Thailand. The present contribution deals with the description of a new genus and species, Thaicypris panhai gen. et sp. nov., which is mainly characterized by the distinctive and raised, inwardly displaced selvage at the postero-ventral part of the right valve (RV) that is not parallel to the valve margin, the absence of an anterior inner list on the RV, the prominent and elevated double inner list on the posterior part of the left valve, the small and three-segmented Rome organ on the first antenna (A1), the spatulated terminal segment of the maxillular (Mx1) palp, the slender caudal ramus (CR) with long and thin Sp seta, the presence of basal triangle on the CR attachment, and the pointed projection at the terminal segment base of the prehensile palps. The hemipenis of the new genus and species is outstanding, especially the medial lateral shield which has a long, beak-shaped protrusion on the distal part. The discovery of this Thai taxon is the first record of the tribe Herpetocypridini in Thailand and the second species of the tribe in Southeast Asia.

First report of three species of the genus Diaphanosoma (Crustacea: Cladocera: Sididae) from Jammu waters (J&K), India

Cladocera, commonly known as ‘water flea’ due to the jerky movements produced by their second antennae, form an important food component for planktivorous fishes and other aquatic invertebrates. The present investigation comprising a collection of zooplankton samples from a shallow pond located in the Bishnah tehsil of Jammu district has revealed the presence of 13 Cladocera species belonging to the families Daphniidae, Chydoridae, Moinidae, Sididae, and Macrothricidae. Three species of the family Sididae belonging to the genus Diaphanosoma, namely, senegal, sarsi and excisum are new species records to the cladoceran fauna of Jammu & Kashmir. Presently, a detailed morphological analysis has been made on all the three Diaphanosoma species. They have shown major differences in their body size with D. senegal being larger than D. sarsi and D. excisum. All three species have well observable variability with reference to their head size, eye size, shell duplicature, shape of posterior valve margin, and the number of denticles so present on posterior valve margin. All the three species have also shown coexistence with each other, but D. senegal was dominant in terms of population density.

Lattice organs and newly characterized submarginal pore-plates and pore-fields of the carapace in Ascothoracida (Crustacea: Thecostraca)

Lattice organs on the dorsal part of the carapace were examined by scanning electron microscopy (SEM) in females, males, and/or cypridiform ascothoracid-larvae (in the ascothoracid-larva I stage, for the first time ever) of six species of Ascothoracida representing four genera and three families: Waginella sandersi (Newman, 1974), W. ?metacrinicola (Okada, 1926), and Gorgonolaureus muzikaeGrygier, 1981 (family Synagogidae); BaccalaureusBroch 1929, unidentified species (Lauridae); and Ascothorax gigasWagin, 1968 and A. synagogoides (Wagin, 1964) (Ascothoracidae). All were of the “keel in a trough” or “tube in a trough” type, but they varied even more than those of previously studied ascothoracidans in number, form, orientation, and terminal pore position. Such extensive variability, summarized graphically herein, limits the potential utility of Ascothoracida (parasites of anthozoans and echinoderms) as an out-group for polarizing lattice organ character-state variation in Cirripedia (free-living and parasitic barnacles). While the ground-pattern of lattice organs in Thecostraca (comprising Ascothoracida, Cirripedia, and Facetotecta, or “y-larvae”) includes two anterior and three posterior pairs, ascothoracid-larvae and males of AscothoraxDjakonov, 1914 and DendrogasterKnipovich, 1890 (family Dendrogastridae) have only two posterior pairs; evidence as to which pair is missing is discussed. The hypothesis that dorsal setae in thecostracan nauplii are the precursors of lattice organs in later developmental stages is reexamined; one-to-one positional matching of such setae to lattice organs is difficult in Ascothoracida. Newly characterized structures of unknown function, termed “reticulated pore-plates”, exist along the hinge line in a juvenile male of G. muzikae. The “pits” reported earlier along the anterior valve margin in ascothoracid-larva II of A. synagogoides are actually clusters of pores that may be homologous to these pore-plates. Potentially homologous pore-fields in other ascothoracidans are reviewed from the literature or described anew using SEM.

Tertiarius minutulus sp. nov. (Stephanodiscaceae, Bacillariophyta) – a new fossil diatom species from Lake Ohrid

A new fossil diatom species, Tertiarius minutulus sp. nov., is described from a sediment sequence DEEP-5045-1 of Lake Ohrid. The species is characterized by small valves (3.0–8.0 µm) with a round shape, a marginal area with radially arranged costae and a central uneven area with scattered areolae. Externally, the alveoli are occluded by cribra perforated by irregularly arranged pores. Internally, the alveoli are simple and areolae are occluded with domed cribra. The marginal fultoportulae are situated on costae close to the valve margin, located on every 5th or 7th thick internal costa. One to three fultoportulae are present on the valve face, each surrounded by two to three satellite pores. One rimoportula is present, positioned on a costa at the valve face / mantle junction. The species is compared with morphologically similar taxa and a detailed differential diagnosis is provided. Tertiarius minutulus sp. nov. is known only as a fossil taxon from Lake Ohrid, with a first occurrence during the early stages of lake basin development.

Neidiopsis borealis sp. nov., a new diatom species from the mountain Shar Planina, Republic of North Macedonia

The genus Neidiopsis is small comprising eight known taxa distributed in oligotrophic to dystrophic freshwater habitats. During observations of diatoms from alpine intermittent ponds on the Shara Mountain, Republic of North Macedonia, a species of Neidiopsis with high abundance was observed. It is characterized by linear to linear–lanceolate valves with a slightly undulated margin, 25.0–43.5 μm long and 6.0–7.0 μm wide. The raphe is filiform with straight proximal and deflected distal raphe endings to the same side of the valve. Striae are partly biseriate near the axial area and continue as uniseriate circular areolae (ca 40 in 10 μm) towards the valve mantle. Striae on each side of the valve are crossed by a prominent longitudinal line located slightly closer to the valve margin. Ultrastructural features of the type population clearly place this taxon into the genus Neidiopsis and aligned to N. levanderi sensu stricto. A similar documented ecotype population (N. levanderi “calcicola”) sensu Lange-Bertalot (2001) is combined with our population and considered a new species N. borealis sp. nov.

Ninastrelnikovia lateritica sp. nov., a new and rare freshwater diatom species from the rocky pools of the Western Ghats, India with a note on the genus Ninastrelnikovia Lange-Bertalot & A.Fuhrmann (Bacillariophyta)

Ninastrelnikovia lateritica sp. nov., a new and rare freshwater biraphid diatom species was discovered from a rocky ephemeral pool of the Kaas plateau, Western Ghats, and described on the basis of light and scanning electron microscopy observations. A morphological comparison with the two other described Ninastrelnikovia taxa is provided. This new species can easily be separated from its congeners by the shape of the valve apex and absence of any second inflation along the valve margin, as well as the shape and structure of the external distal raphe ends and internal proximal raphe ends. The members of Ninastrelnikovia are characterized by two morphological types of valves. Valves on the ends of colonies exhibit one set of morphological features while valves located in the middle of colonies show another set of morphological features. Morphological details of the valves are discussed.

Planothidium sheathii, a new monoraphid diatom species from rivers in California, USA

Planothidium sheathii sp. nov., a new species from rivers in California, USA, is described based on light and scanning electron microscopy. P. sheathii has broadly lanceolate to elliptic valves with obtusely rounded apices and a unique combination of morphological features, as follows: 1) cavum with broad hood aperture that flares out at the valve margin with open borders fused with the neighboring virgae on SV, 2) multiseriate striae, composed of five to six rows of same sized areolae on both valves, interrupted at valve mantle junction, and 3) areolae groups on valve mantle, with rounded areolae on RV, and rounded and elongated areolae on SV. Valve morphology of P. sheathii is discussed in comparison with similar freshwater taxa, from which the new species is clearly distinct.

Tiny diatoms Minidiscus vodyanitskiyi sp. nov. (Bacillariophyta) from the Sea of Azov and consideration of polygonal areolae pattern

A new tiny species of Minidiscus, M. vodyanitskiyi, was found in the water column collected from the central part of the Sea of Azov. Its morphology was examined by scanning electron microscopy, described and illustrated. This centric diatom is characterized by: 1) small valve diameter of less than 10 µm; 2) one central fultoportula surrounded by two satellite pores located opposite each other; 3) one rimoportula located one areola away from the central fultoportula which internally appears similar to a slit surrounded by a plan elliptic rim oriented radially or slightly tangentially; 4) 4–6 (10) marginal fultoportulae that are equally spaced on a border between the valve surface and valve mantle; 5) three satellite pores that surround every marginal fultoportula, where a central satellite pore is directed towards the valve margin; 6) hexa- or heptagonal pattern of valve areolae; and 7) a hyaline conical flange connects the cingulum with the valve. The new species is compared with similar ones. A new term ‘polygonal areolae pattern’ is proposed instead of ‘eccentric pattern’. The term emphasizes that the pattern comprises concentric polygons formed by tangential areolae rows. Its qualitative characteristic, ‘polygonality’, has been described which allows more precise differentiation of the geometry of the valve pattern and describing areolae size variability.

Taxonomic revision and morphological cladistics analysis of the diatom genus Anorthoneis (Cocconeidaceae), with description of Anorthoneis arthus-bertrandii sp. nov.

We present here an ultrastructure-based revision of the diatom genus Anorthoneis using both light (LM) and electron microscopy (SEM). The original slides and type material of all known Anorthoneis species were analysed and new, previously unseen, morphological features of the frustules, such as rota-like vela and ligulate structures around the valve margin, were revealed. The phylogenetic relationships among Anorthoneis taxa were investigated based on morphological characters using a maximum parsimony method. This analysis indicated a large, well-supported clade that included taxa that exhibited similarities in external and internal details of the central areas in both raphe-sternum and sternum valves. Revealed synapomorphies within the genus include externally and internally transversely dilated central area on both sides of the raphe-sternum valve, externally transversely dilated central area on both sides of the sternum valve, sternum valve striae parallel at the center and radiate at the apices, and areolae with hymenes in both valves. During a survey a new species Anorthoneis arthus-bertrandii sp. nov., was found on seagrass leaves collected from Siladen Island (Indonesia). This taxon is sister to A. hyalina, but can be easily differentiated from the latter by smaller valve dimensions, central area size and shape, and rota-like vela occluding sternum valve areolae - a feature that has never been observed in other Anorthoneis taxa.

Nupela major sp. nov., a new diatom species from Maolan Nature Reserve, central-south of China

Nupela major sp. nov., a new species of the diatom genus Nupela, is described from Maolan Nature Reserve, Guizhou Province, China. Observations were made using light and scanning electron microscopy documenting the size, shape and ultrastructure of the new species. Valves of the monoraphid frustules are elliptical-lanceolate with more or less cuneate, subtlety protracted ends. The raphe valve has a linear-lanceolate axial area and an irregularly-shaped central area. Striae appear intermittent or disrupted. The rapheless valve has a linear-lanceolate axial area widening in the center to form an asymmetrical central area that can in some specimens reach to the valve margin. The rapheless valve has a contoured valve face, with deep indentations in the axial area. The species is assigned to Nupela by virtue of its external occlusions on the areolae, and compared with similar species in the genus. The new species is found on stones beneath a waterfall and associated with a moss community.