Convex Valve Research Articles

Identifikasi Keragaman Plasma Nutfah Bunga Telang (Clitoria ternatea L.) Di Provinsi Maluku Utara

The Clitoria ternatea plant which has the common name flower telang is a perennial shrub that has deep and woody roots, slightly upward or upright and climbing stems with a height between 20 - 90 cm, downy hair, three to five leaves, oval leaflets the upper surface is hairless and the lower surface is scattered with hairs, flowering bunches in the armpits with 1-2 flowers, the length of the petiole is up to 4 cm, the petals are purple to almost white, the pods are spun oval, hairless, seeds 3-7 , convex valve, seeds round to ovate, brownish in color. The research objective was to determine the diversity of clitoria ternatea flower plants in North Maluku province and as a breeding material for the development of telang flower plants. This research uses descriptive method with direct observation techniques on the object being observed. Morphological and agronomic character data were obtained through surveys and direct observation of sample plants in the field based on modified telang plant descriptor guidelines (IBPGR, 1983 and e-Floras, 2010). From the research found 14 accessions of Clitoria ternatea in North Maluku Province and showed diversity in leaf color, leaf length, leaf length, leaf width, leaf blade size, leaf shape, leaf stalk length, protective crown size, pod length, pod width. pod color, degree of pod curvature, shape of pod beak curvature, seed color, seed coat glossy, number of seeds / pods, maximum number of ovules / pods, weight of seeds / seeds, weight of seeds / pods. The kinship relationship of 14 accessions, cluster I level of similarity 50.55%, cluster II 60.75% and cluster III 42.31%.Keywords: Telang Flower, Germplasm, Diversity

Fragilaria subrecapitellata (Fragilariaceae, Bacillariophyta), a new diatom species from Switzerland

During a biomonitoring assignment in the Swiss canton Ticino, an unknown Fragilaria taxon was discovered that could not be identified using the currently available literature. The results of a morphological comparison with the type material of F. recapitellata, based on light and scanning electron microscopy, showed that the new Swiss taxon has sufficient differences to be separated as a new species: Fragilaria subrecapitellata sp. nov. The new species can be separated by its lanceolate to elliptic-lanceolate valve outline with convex valve margins, and its smaller valves compared to F. recapitellata. The distribution and iconography of F. recapitellata in literature data is analysed. As a result of this analysis, Fragilaria deformis is appointed as the correct name for the taxon generally known as F. candidagilae or F. capucina var. capitellata (Grunow) Lange-Bertalot in Krammer & Lange-Bertalot.

The effects of shellfish harvesting by aboriginal inhabitants of Southwest Florida (USA) on productivity of the eastern oyster: Implications for estuarine management and restoration

Abstract Oyster reefs in Southwest Florida (USA) have been integral to estuarine ecology throughout the Holocene. Though Crassostrea virginica has never been commercially harvested, aboriginal people used the oyster substantially, accumulating middens between 5000 BC and AD 1700. A conservation paleobiological/historical ecological study of oysters from middens and modern reefs within Estero Bay (EB) and Pine Island Sound (PIS) determined if oyster productivity changed due to aboriginal overharvesting. Archaeological samples came from sites including the Late Archaic (LA, 2000–500 BC) of PIS and the Caloosahatchee (Cal, 500 BC–AD 1500) of EB and PIS. These samples were compared with natural oyster death assemblages from neighboring modern reefs. Methods comprised measuring oyster convex valve lengths and sectioning shells to count ligament pit growth lines that served as proxy for growth rate. The biologic taphonomic grade was also compared after scoring the interior valve surface; biologic grade is near pristine for oysters collected live for consumption. Archaeological samples exhibit significantly better taphonomic grades when compared to modern assemblages, confirming the hypothesis that oysters were harvested for food. Valve length decreased significantly from LA to Cal time, whereas modern assemblages were indistinguishable from LA collections. Because the Cal samples span 4 climatic intervals, the results suggest that climate change was not responsible for shifts in productivity. Results support the hypothesis of overharvesting during Cal times. They also suggest that modern oysters retain the capacity for growth, and indicate that aboriginal activity did not result in a permanent microevolutionary shift. The results are also relevant for the ongoing discussion surrounding the creation of an Anthropocene Epoch; the shell middens built throughout history greatly influenced both estuarine ecology and landscapes through fishing and engineering practices.

Cymbelloid diatoms (Bacillariophyta) of relict Lake Mogilnoye (Kildin Island, Barents Sea)

New data on morphology of 7 pennate diatom species from the order Cymbellales found in subpolar meromictic Lake Mogilnoye, are presented. A new species, Rhoicosphenia murmanica Gogorev et E. Lange, sp. nov., is described. Its frustules are 13–40 μm long, 3.5–6 μm wide, 4–9 μm high and have 16–20 striae per 10 μm on the convex valve and 14–18 on the concave valve. The new species is characterized by a variable length of diminutive raphe branches on convex valve (1/6–1/3 of valve length). R. murmanica is similar to R. adriatica, R. baltica, R. marina and R. omblaensis in size of valves and number of striae, but differs in valve outline, number of striae, or width of valves. All the species are found for the first time in the lake. Cymbopleura frequens is recorded in the first time for the flora of Russia; four taxa, Encyonema minutum, E. silesiacum, Geissleria acceptata and Placoneis clementioides are recorded for the first time in the flora of the Murmansk Region.

A new gelatinous colony-forming Thalassiosira minicosmica sp. nov. (Bacillariophyta) from Korean coastal waters and a consideration of the Thalassiosira subtilis group

A new, convex-valved Thalassiosira species, T. minicosmica, was observed from Korean coastal waters between 6 May 2009 and 6 March 2014. Thalassiosira minicosmica was characterized by: (1) gelatinous colony formation by mucilage threads extruded from the fultoportulae, (2) eccentric arrangement of the areolae, (3) almost occluded foramina, (4) a short external tube of marginal fultoportulae, and (5) a single rimoportula (with a remarkably long external tube) between marginal fultoportulae. Similar species, such as T. minuscula, T. diporocyclus and T. subtilis, were compared with T. minicosmica, and their several shared characters, such as the convex valve, foramen structure and an externally larger rimoportula than fultoportula, are diagnostic for the Thalassiosira subtilis group, rather than the gelatinous colony-forming feature. Based on the morphological similarities, we recognize the Thalassiosira subtilis group including seven Thalassiosira species.

Rhoicosphenia michali: a new species of marine diatom (Bacillariophyta) from King George Island, Antarctica

Rhoicosphenia michali sp. nov., described from the shallow sublittoral zone in Antarctica, is the second species in the genus with just one raphe slit on its convex valve. The first species, Rhoicosphenia flexa, was also described from marine coastal habitats in the Southern Hemisphere. Here, the morphology and ecology of R. flexa and R. michali are compared. The new species described herein may be endemic to Antarctica and can be found as free living cells on the shallow seabed, although it mainly occurs on the red alga Georgiella confluens, which is endemic to Antarctica.

Rhoicosigma parvum n. sp., a benthic marine diatom from The Bahamas and Western Pacific

A new diatom species, Rhoicosigma parvum Hein & Lobban, is described from benthic marine macroalgae and seagrasses northwest of Andros Island, The Bahamas, and from macro- and filamentous seaweeds of Guam and Palau. Specimens observed ranged in length from 30 to 70 µm, and in width from 6 to 9 µm, with 29–32 transverse striae in 10 µm. The frustule is slightly sigmoid in valve view and arched in girdle view. The two valves are dissimilar. The convex valve has an almost-straight raphe and the concave valve has a strongly sigmoid raphe. The chloroplasts are deeply lobed plates, one along each side of the girdle. Scanning electron microscopy revealed that the valves have loculate areolae, with the areolae opening to the valve exterior as apically elongated slits. By contrast, the internal areolar openings are rectangular, elongated apically. Externally, the central raphe endings are deflected in the same direction and terminate in pore-like expansions. The terminal fissures are strongly bent in opposite directions and in the same direction as the sigmoid curvature of the valve end. Internally, the central raphe branch endings are simple and straight, whereas the apical raphe endings terminate in well-developed helictoglossae. There are siliceous thickenings (central bars) on both sides of the central nodule. Specimens are similar to R. compactum (Greville) Grunow but are smaller and have finer striae.

A reappraisal of the genus Leptocylindrus (Bacillariophyta), with the addition of three species and the erection of Tenuicylindrus gen. nov.

Centric diatoms of the genus Leptocylindrus are common in the marine plankton worldwide. Only two species, L.danicus Cleve and L.minimus Gran, so far clearly belong to this genus, whose diversity has not been fully investigated. We investigated frustule and spore morphology as well as three nuclear- and three plastid-encoded markers of 85 Leptocylindrus strains from the Gulf of Naples, and one from the Atlantic US. The strains grouped into five molecularly distinct species with different levels of morphological differentiation. Two species matched the description of L.danicus and produced similar spores but differed in morphometric characters and sub-central pore position, supporting the description of L.hargravesii Nanjappa and Zingone as a distinct species. Leptocylindrus danicus var. apora French III and Hargraves, lacking a sub-central pore and not forming spores, was raised to the species level as L.aporus (French III and Hargraves) Nanjappa and Zingone. A fourth species with convex valves was described as L.convexus Nanjappa and Zingone. The fifth species matched the description of L.belgicus Meunier, considered as synonym of L.minimus. However, ultrastructural differences from all other Leptocylindrus supported the erection of the genus Tenuicylindrus Nanjappa and Zingone with T.belgicus (Meunier) Nanjappa and Zingone as type species. None of the sequences matched the L.minimus sequence in GenBank. The species analyzed showed different or partially overlapping seasonal distributions. Despite the addition of the new taxa, the ancient diatom lineage of the Leptocylindraceae shows a relative species poorness and considerable morphological stasis.

Functional morphology and taphonomy of Cenomanian (Cretaceous) oysters from the eastern Sinai Peninsula, Egypt

The morphological variability of the soft-bottom oysters Ilymatogyra africana (Lamarck, 1801), Costagyra olisiponensis (Sharpe, 1850) and Chondrodonta joannae (Choffat, 1886) from the Cenomanian of eastern Sinai is interpreted in terms of ecophenotypic response to environmental parameters. In I. africana, the influence of coiling and shape of the left valve on the concavity and outline of the right valve can be demonstrated. Type and stability of the substrate also influenced the shell microstructure: In early growth stages, the layers are conformable, becoming unconformable during later growth stages. This unconformity and the pronounced thickening of the dorsal region of the left valve is interpreted to have led to a re-orientation of the organisms in the sediment, thereby protecting them from the danger of becoming buried and of their gills becoming clogged. The three-dimensional spiral growth and high vertical increment of forma typica of I. africana also protected the organisms from becoming buried. The high degree of disarticulation and the concentration of Ilymatogyra shells suggest reworking due to winnowing and bioturbation. In C. olisiponensis, juveniles were cemented to secondary hard substrates, whereas adults were adapted to a free reclining mode of life. Taphonomic analysis of C. olisiponensis shells suggests a lack of reworking and low rates of sedimentation. There exists a relationship between the size of the attachment area and the shell outline and convexity of C. olisiponensis, with a small attachment area occurring in individuals with a wide postero-ventral part and less convex valves and a large attachment area occurring in more elongated shells with strongly convex valves. Chondrodonta shell concentrations occur in various preservational states, which reflect the gradual mixing and mechanical destruction of a former community. Storm-induced waves and currents as well as reduced sediment input were responsible for their formations.

First Colour-Patterned Strophomenide Brachiopod from the Earliest Devonian of Podolia, Ukraine

Retained colour pattern on the shells of Plectodonta sp. from the earliest Devonian of Podolia (Ukraine) is the first finding for strophomenide brachiopods and the oldest among articulate brachiopods. The colour pattern in Plectodonta sp. is composed of small, round, brownish spots scattered rather irregularly on the ventral valve only. This may suggest that the described pattern probably performed a protective function through disruptive camouflage against visual systems of potential predators. The occurrence of the colour pattern in Plectodonta sp. exclusively on the ventral valve strongly suggests that these brachiopods lived with the patterned (and convex) ventral valve upwards and the patternless concave dorsal valve facing to the underlying substrate. It thus contradicts a general assumption that concavo-convex brachiopods lived with their convex valves resting on the sediment.

A taxonomical study of Rhoicosphenia Grunow (Bacillariophyceae) with a key for identification of selected taxa.

A taxonomical study of 15 Rhoicosphenia species based on light and scanning electron microscope was performed. The genus Rhoicosphenia is characterized by frustule heterovalvy, with a fully developed raphe on the concave valve (referred also as R valve) and reduced raphe on the convex valve (referred as D-valve). One of the most frequently reported species, R. abbreviata, is characterized by narrow, linear valves with low stria density. In contrast, Rhoicosphenia macedonica has broadly clavate valves with a high stria density. According to valve shape R. macedonica is similar to the widely distributed marine species R. marina, but the latter has broader valves (8.5-11 μm wide) and a lower stria density. Both, R. tenuis and R. baicalensis have similar valve sizes and shapes, but the latter is characterized by a lower stria density on the D-valve. Rhoicosphenia baltica is a brackish water species with protracted and subcapitate base poles, narrower valves and lower stria density compared with R. marina. The main distinctive features of R. flexa are the absence of a raphe branch on the head pole of the convex D-valve, and coarsely punctate striae. R. genuflexa has isopolar, linear valves. Four other species have different combinations of characters (valve size, shape and stria density) compared to above mentioned species, and their formal descriptions are provided. Rhoicosphenia lacustris sp. nov. is characterized by larger and broadly clavate valves, densely spaced striae and elongated areolae. Rhoicosphenia affinis sp. nov. has broadly lanceolate valves with attenuated and slightly protracted head pole with a higher stria density compared to R. abbreviata. Rhoicosphenia adriatica sp. nov. is a brackish water species having narrow, linear valves, with a high stria density. Finally, R. omblaensis sp. nov. has a characteristic central area, which appears as a narrow hyaline area around the central pores.

Two new Cocconeis taxa (Bacillariophyceae) from coral sands off the Mascarenes (Western Indian Ocean) and some related unidentified taxa

Coral sands off Réunion Island and Rodrigues (Mascarene archipelago, Western Indian Ocean) support diverse diatom communities, particularly rich in Monoraphidineae. Recent surveys of reef environments (June 2005 and June 2007) permitted the recognition of several taxa belonging to the diatom genus Cocconeis, among which are two new, relatively small taxa, epipsammic on coral sand. Cocconeis coronata Riaux-Gobin et Romero sp. nov. is similar to C. scutellum but has its own distinctive features. In external view, the concave raphe valve possesses uniseriate striae and a subsident hyaline marginal rim, while the strongly convex sternum valve has a submarginal, generally continuous crest, a hexagonal pattern of areolation, short, rounded spines that are often regularly arranged around valve face areolae, a complex areola hymen and small marginal chambers. Some morphometric differences were noted between the populations of C. coronata at Réunion and Rodrigues. Cocconeis margaritata Riaux-Gobin et Al-Handal, sp. nov. is smaller, possesses a sternum valve like that of C. placentula and C. neothumensis, but has denser striation and small pearl-like concretions around the areola aperture on the sternum valve. Several other taxa that resemble, or may be varieties of, C. margaritata require further study before being formally described. Cocconeis margaritata and C. coronata are small and relatively rare, so their study requires scanning electron microscopy.

RHOICOSPHENIA TENUIS, A NEW DIATOM SPECIES FROM LAKE OHRID

A new Rhoicosphenia species, R. tenuis Levkov & Nakov is described from Lake Ohrid. It is characterized by its narrow linear valves (valve width up to 4.5 μm), which differentiate it from the otherwise similar R. curvata. This species has an ultrastructure typical of the rest of the freshwater representatives of the genus Rhoicosphenia. The concave valve possesses the typical raphe system, while the convex valve has a reduced raphe system. A well developed pseudoseptum is present at the poles, and both valves possess an apical pore field at their foot pole. According to valve morphology and ultrastructure, R. tenuis is closer to R. curvatathan to Rhoicosphenia macedonica, another species described from Lake Ohrid,

THALASSIOSIRA RUDIS SP. NOV. (COSCINODISCOPHYCEAE): A NEW FRESHWATER SPECIES

The centric diatom Thalassiosira rudis sp. nov. has been described by morphological and ultrastructural analyses of the frustules using light and scanning electron microscopy. The species was found in the freshwater ecosystems from Brazil. T. rudis is characterized by a convex valve face sunken in the middle and downturned at mantle, wider central areolae, internal opening of cribra branched in dichotomic rows, absence of central processes, 1–3 marginal rimoportulae, presence of marginal ring of fultoportulae with inward extension furnished with cowlings and very short external tube, cingulum composed of four or more open bands, singly and alternately septate, and valvocopulae with one row of larger poroids. The new species was compared morphologically with closely related species ofThalassiosirasuch as T. gracilis (Karsten) Hustedt, T. visurgis Hustedt and T. rudolfii (Bachman) Hasle. Comments about T. weissflogii (Grunow) Fryxell & Hasle and T. leptopus (Grunow) Hasle & Fryxell were presented.

STEPHANODISCUS KUETZINGII KLEE & CASPER (BACILLARIOPHYCEAE) FROM LIVING MATERIAL COLLECTED IN RAPEL RESERVOIR, CENTRAL CHILE

Stephanodiscus kuetzingii Klee & Casper, described from a Pleistocene deposit in the Lüneburger Heide, Lower Saxony, Germany (Kützing type material for Cyclotella minutula), was found living in Rapel Reservoir, Central Chile. There are no published records of living material for this species. Its valve morphology was studied using light and scanning electron microscopy. The morphological features of the Chilean specimens are in good agreement with those of S. kuetzingii described by Klee and Casper. The present study provides additional information on rimoportula structure, in which a long external tube was observed, as well as on the presence of a narrow circumferential hyaline area at the valve face/mantle junction of convex valves. The similarities and differences between S. kuetzingii and other closely related Stephanodiscus species are discussed.

CYCLOSTEPHANOS KYUSHUENSIS SP. NOV. FROM PLIOCENE SEDIMENTS IN SOUTHWESTERN JAPAN

Cyclostephanos kyushuensis sp. nov. is described from a Pliocene diatomite in Kyushu, southwestern Japan. The species is characterized by different morphologies of its convex and concave valves. The convex valves have shorter costae; those bearing a rimoportula or fultoportula extend to valve edge while the others do not. The concave valves have longer costae, all of which do not extend to valve edge in either external or internal views. Though the costae of some Cyclostephanos do not extend to valve edge, the presence of costae that do in convex valves and costae that do not in concave valves of the same frustule is unique for the genus. The new species is compared to similar species of Cyclostephanos: C fenestratus Theriot & Kociolek, C. delicatus (Genkal) Kling & Håkansson, C. dubius (Fricke) Round and C. numataensis Tanaka & Nagumo.

DIPRORA HAENAENSIS GEN. ET SP. NOV., A FILAMENTOUS, PSEUDOAERIAL, ARAPHID DIATOM FROM KAUA'I (HAWAIIAN ISLANDS)

Diprora haenaensis gen. et sp. nov. Main, an araphid filamentous diatom, is described from a cryptic, pseudoaerial habitat in Kaua'i, Hawaiian Islands. The valve ends of this new diatom have pervalvar extensions of the mantle edges, termed here prows. The frustules are heavily silicified and usually heterovalvar (one valve surface convex and the other concave). Convex and concave valves have different orientations of the row of marginal pores. The prows of the valves overlap in intact frustules. Each epicingulum consists of the two prows and two lateral band segments, one on each side of the frustule between the prows. The hypocingulum has a similar shape and orientation, but is hidden inside the epicingulum and hypovalve margin. In other words, a valvocopula consists of two bands, one on each side of the frustule separated by the two prows of the valve. The fimbriae of the pars interior of the valvocopula are flap-like. The frequency of post-auxospore stages, valve size distribution, and possible occurrence of resting spores are discussed. The association of heterovalvy with filament formation is more suggestive of centrics than pennates; however, its symmetry, valve and pore ultrastmcture, and life history taken together are more indicative of a pennate affiliation. Diprora appears to belong to the Fragilariophycidae, but the most similar genus within that class is Hyalinella.

Intraspecific variation during the life cycle of a modern Stephanodiscus species (Bacillariophyceae) inferred from the fossil record of Lake Suigetsu, Japan

Stephanodiscus populations were studied from a sediment core from Lake Suigetsu, central Japan. The cells were assignable to two modern freshwater species, S. suzukii and S. pseudosuzukii, described recently from Lake Biwa, which closely resemble S. carconensis and its varieties from Neogene lacustrine sediments in North America. Wide, continuous morphological variation, such as in the degree of central undulation, raised costae, number of central fultoportulae, and ultrastructure of the rimoportula internal opening, was observed in the populations, which consisted of convex, concave, and hemispherical valves. The diameters of convex and concave valves ranged from 5 to 45 μm, with a predominance of small ones measuring 7–12 μm; hemispherical valves, representing initial cells, were 25–50 μm in diameter and their morphological features were homogeneous. The size distributions indicate that the hemispherical valves are the initial valves of all the convex and concave vegetative valves, which show continuous variation in size and morphology. All valves therefore belong to the same species and so we reduce S. pseudosuzukii to being a synonym of S. suzukii. We describe for the first time life-cycle–related changes in the morphology of the rimoportula internal openings: the stalked, fan-shaped rimoportula in initial or large valves changes progressively to smaller and finally sessile forms, indicating the need for caution during taxonomic interpretation of this character in other diatoms.

PARALIA ELLIPTICA SP. NOV., AN EPIPSAMMIC DIATOM FROM SANTA CATARINA STATE, BRAZIL

This paper is part of a Ph.D. thesis at Universidade Federal do Rio Grande do Sul A new centric diatom, Paralia elliptica Garcia, is described from marine surface sand collected in Zimbros Bay, Araçá, Penha, Praia Brava and Taquarinhas (Santa Catarina State, Brazil), where it lives as an epipsammic species. The taxon is characterized by its elliptical outline, convex valve, gently undulate valve face with parallel ridges and grooves, heterovalvy and a ring of rimoportulae oriented obliquely to the striae. The morphology and ultrastructure of valves and frustules are described by light microscopy (LM) and scanning (SEM) and transmission electron microscopy (TEM) observations.

VALVE MORPHOGENESIS IN THE MARINE ARAPHID DIATOM GEPHYRIA MEDIA (BACILLARIOPHYCEAE)

Valve morphogenesis in the marine araphid diatom Gephyria media W. Arnott was studied using dense populations epiphytic on red algae. Valves begin as a narrow sternum with virgae (pinnate lateral outgrowths). The apical pore fields and rimoportulae at each end of the concave valve are produced early in valve morphogenesis. The rimoportulae of the convex valve are also formed early and the virgae are branched at the apex. The timing of rimoportula formation well after formation of the virgae appears to contradict the hypothesis that the raphe system may have evolved from rimoportulae of araphid diatoms. Formation of the bi- and triseriate striae begins at the sternum with the lateral outgrowth of forked vimines, which then fuse. Completion of valve morphogenesis involves the development of an internal silica sheet. When the sheet is fully extended it forms an internal zigzag pattern of foramina near the valve margin in both kinds of valves, thus producing chambers. The rimoportula lengthens internally and in the final process forms the labiate process upon a stalk. Delicate internal rotae were observed in mature valves. Several features of valve morphogenesis in G. media are similar to those observed in other araphid and raphid species. The apical pore field develops in a manner similar to that of Gomphonema, the chambering as in Pinnularia and Catacombas and the rimoportula as in Diatoma.