Species Research Articles

Asymptotic properties of an optimal principal Dirichlet eigenvalue arising in population dynamics

We consider a shape optimization problem related to the persistence threshold for a biological species, the unknown shape corresponding to the zone of the habitat which is favorable to the population. Analytically, this translates in the minimization of a weighted eigenvalue of the Dirichlet Laplacian, with respect to a bang-bang indefinite weight. For such problem, we provide a full description of the singularly perturbed regime in which the volume of the favorable zone vanishes, with particular attention to the interplay between its location and shape.First, we show that the optimal favorable zone shrinks to a connected, nearly spherical set, in C1,1 sense, which aims at maximizing its distance from the lethal boundary. Secondly, we show that the spherical asymmetry of the optimal favorable zone decays exponentially, with respect to a negative power of its volume, in the C1,α sense, for every α<1. This latter property is based on sharp quantitative asymmetry estimates for the optimization of a weighted eigenvalue problem on the full space, of independent interest.

Effects of the Three Gorges Dam on the mandarin fish larvae (Siniperca chuatsi) in the middle reach of the Yangtze River: Spatial gradients in abundance, feeding, growth, and survival

AbstractLarge dams significantly impact river ecosystems by disrupting connectivity, altering physicochemical variables, and modifying flow regimes. These modifications influence the spatial and temporal dynamics of biological processes and species distributions. While much research has focused on potamodromous species, there remains a gap in understanding the recovery gradients of resident species in dam‐altered rivers. This study examines the responses of larvae of a resident species, the mandarin fish (Siniperca chuatsi), to environmental alterations caused by the Three Gorges Dam (TGD) in the middle reach of the Yangtze River. We hypothesized that larval abundance, feeding, growth, and survival would exhibit longitudinal recovery gradients, improving with the increased distance from the TGD. Our results confirm this hypothesis, showing that larvae further from the TGD exhibited higher abundance, increased feeding intensity, enhanced growth rates, improved survival rate, and earlier peak abundance and hatching dates. Key environmental factors, including water temperature and discharge, increased downstream, while transparency decreased. Major tributary inputs significantly contributed to these recovery gradients. The observed longitudinal gradients in larval attributes mirrored environmental changes, underscoring the TGD impact on population recruitment. These results highlight the broader implications of dam‐induced changes on resident species recruitment, potentially affecting entire fish communities. Our study contributes to understanding the distinct spatial patterns of population trends, providing valuable insights for designing more effective conservation and management practices for resident freshwater fishes in large regulated rivers.

Construction of a Near-Infrared Fluorescent Probe for Dynamic Monitoring and Early Diagnosis of Heart Failure.

Cardiac hypertrophy characterized by abnormal cardiomyocyte viscosity is a typical sign of heart failure (HF) with vital importance for early diagnosis. However, current biochemical and imaging diagnostic methods are unable to detect this subclinical manifestation. In this work, we developed a series of NIR-I fluorescence probes for detecting myocardial viscosity based on the pyridazinone scaffold. The probes showed weak fluorescence due to free intramolecular rotation under low-viscosity conditions, while they displayed strong fluorescence with limited intramolecular rotation in response to a high-viscosity environment. Among them, CarVis2 exhibited higher stability and photobleaching resistance than commercial dyes. Its specific response to viscosity was not influenced by the pH and biological species. Furthermore, CarVis2 showed rapid and accurate responses to the viscosity of isoproterenol (ISO)-treated H9C2 cardiomyocytes with good biocompatibility. More importantly, CarVis2 demonstrated excellent sensitivity in monitoring myocardial viscosity variation in HF mice in vivo, potentially enabling earlier noninvasive identification of myocardial abnormalities compared to traditional clinical imaging and biomarkers. These findings revealed that CarVis2 can serve as a powerful tool to monitor myocardial viscosity, providing the potential to advance insights into a pathophysiological mechanism and offering a new reference strategy for early visual diagnosis of HF.

Bovine Serum Albumin Bends Over Backward to Interact with Aged Plastics: A Model for Understanding Protein Attachment to Plastic Debris.

Plastic pollution, a major environmental crisis, has a variety of consequences for various organisms within aquatic systems. Beyond the direct toxicity, plastic pollution has the potential to absorb biological toxins and invasive microbial species. To better understand the capability of environmental plastic debris to adsorb these species, we investigated the binding of the model protein bovine serum albumin (BSA) to polyethylene (PE) films at various stages of photodegradation. Circular dichroism and fluorescence studies revealed that BSA undergoes structural rearrangement to accommodate changes to the polymer's surface characteristics (i.e., crystallinity and oxidation state) that occur as the result of photodegradation. To understand how protein structure may inform docking of whole organisms, we studied biofilm formation of bacteriaShewanella oneidensison the photodegraded PE. Interestingly, biofilms preferentially formed on the photodegraded PE that correlated with the state of weathering that induced the most significant structural rearrangement of BSA. Taken together, our work suggests that there are optimal physical and chemical properties of photodegraded polymers that predict which plastic debris will carry biochemical or microbial hitchhikers.

Taxonomy and systematics of the Neotropical primates: a review and update

The database of the IUCN SSC Primate Specialist Group currently (December 2023) registers 218 species and subspecies of Neotropical primates in 24 genera and five families. In the early 1960s, the diversity of Neotropical primates was estimated to be around 200 species and subspecies. From then, through the 1970s to the mid-1990s, however, the perception of the region’s primate diversity dropped, and reached an all-time low at 83 species and subspecies in 1980 (A World List of Mammalian Species, G. B. Corbet and J. E. Hill, British Museum (Natural History), Comstock Publishing, Cornell University Press, London and Ithaca). Interest in taxonomy and primate field research in the Neotropics was subdued up to the late 1970s. Change was sparked by the burgeoning capture of primates for biomedical research in the 1950s and 1960s, and the increasing destruction of the Amazon rainforests from the late 1970s. The numbers increased, at first slowly, but then, in 1995, they leapt back to the 200s in anticipation of a book by C. P. Groves (2001, Primate Taxonomy, Smithsonian Institution Press, Washington, DC). The species’ counts (not including subspecies) rose due to the adoption of the Phylogenetic Species Concept over the Biological Species Concept, the former favoring the category of species over subspecies. In this article, we discuss the changes in species and subspecies numbers in the classification of the Neotropical primates, and report on the taxonomic changes resulting from taxonomic research ongoing since 2012. We emphasize the importance of taxonomic research for an understanding of the diversity of primates, and for conservation planning, not least in identifying the populations that are threatened.

Integrative taxonomic revision of the African thicket rats (Murinae: Grammomys): how genomics decreases the number of currently recognized species

Abstract Thicket rats of the genus Grammomys are partly arboreal rodents distributed across a large part of sub-Saharan Africa. Previous work showed that their highest diversity is in forests and woodlands of Eastern Africa, that the evolutionary history of the genus roughly mirrors the evolution of African forests, and that the currently delimited species (names) do not correspond to major genetic clades. We used thousands of single nucleotide polymorphisms to perform phylogenomic analysis and to delimit genomic pools (i.e. candidate biological species). The resulting molecular operational taxonomic units were then compared with the most comprehensive sets of other available data (mitochondrial DNA variability, ecological requirements, morphology, karyotypes, sequences from the type material, etc.) and used for an integrative solution to the taxonomy of the genus. Our revision delimited seven species, which is less than the 12 recognized in the most recent literature on African rodents. We conclude that the African thicket rats represent a classic example of challenging problems in current integrative taxonomy. It is now relatively easy to obtain genomic data and to delimit candidate species, but it is much more complicated to give them species names using the valid rules of zoological nomenclature.

Asclepiadaceae of Maharashtra

Family Asclepiadaceae is represented by 250 genera and ca 3000 species mainly distributed in tropical and subtropical regions of the world. It is represented by 43 genera and ca 243 species in India, of which, 31 genera, 82 species, 2 subspecies and 7 varieties are known from the State of Maharashtra. The family is well known for endemism, most elaborate complicated flower of all the dicots and contrivances for pollination. Most of the members of the family are restricted in distribution and many of them fall under some IUCN categories of rare plants. Many of the species are not available for taxonomic studies due to rarity of plant materials. Similarly fleshy nature of flowers makes it difficult to study floral structure in dried herbarium specimens. During last decade, deliberate attempts were made to collect asclepiads of Maharashtra and study their characters in fresh and prickled liquid preserved materials. During 10 years intensive survey of asclepiads of Maharashtra, about 63 species of the total 82 species reported for the State have been collected, documented, photographed, studied and reported in the present paper. The genus Ceropegia alone accounts for 24 species and 2 varieties for the state. Photographs of asclepiad flowers are found to be of paramount value in easy identifications than their descriptions. The paper gives an account of Asclepiads of Maharashtra, their distribution and present field status.

Botany of Mt. Saramati and its Environs

The paper gives a brief account of botany of Mt. Saramati in Nagaland, India which represents the state's highest mountain peak (3841m), the remotest and the botanically unexplored area. A brief note on topography, geology, climate and vegetation together with a comprehensive analysis of the floristic compositions of the vegetation types and is followed by enumeration of the species of angiosperms and gymnosperms. Analysis of the species collected established the following five families as the richest ones on the basis of the number of the species. Orchidaceae (25), Poaceae (24), Asteraceae (17), Ericaceae (13), Cyperaceae (9). These together represent about 40% of the total number of species collected. All the species recorded in this paper, except Deyeuxia pulchella (Griseb.) Hook. f. (Poaceae) are new additions to the Kanjilal's Herbarium (ASSAM) from the area. There is also no record of any representation of plant species from there by Clarke (1886, 1889), Hooker (1872-97), Kanjilal et al. (1934-40), Bor (1942), Jamir and Rao (1088). The present paper, therefore, represents the first source of information regarding botany of the Mt. Saramati.

Ethnomedicinal Plants of Betul District, Madhya Pradesh

The paper deals with ethnomedicinal information on 54 plant species (belonging to 33 families) collected from field survey amongst three tribes viz., Gond, Korku and Gaiki of Betul district, Madhya Pradesh. An analysis of data has indicated that eight plant species are employed as antidote to snake bite and scorpion sting, six to treat fever. five for rheumatism, four to treat cold, cough, skin diseases, as anthelmintic and tonic, and three for stomach diseases while two species to treat impotency, cuts, wounds and as diuretic. On the other hand, only single species has been referred for a number of other ailments like eye diseases, spermatorrhoea, spleen enlargement, tuberculosis, mouth sore, boil, asthma, liver disorder, toothache, bone fracture, abortifacient, antifertility, and in veterinary. Further, a comparison with the concerned literature has revealed that 23 ethnomedicinal uses of plants have not been reported earlier.

Some Additional Information on the Ethnobotany of Rajasthan

This paper attempts to document the ethnobotanical information of some thirty unreported species of Sariska National Park located in the Aravalli hills of eastern Rajasthan. Out of 30 species, 22 are of medicinal and 8 species are of food value.

Pollen Morphology of some Species of Rhamnaceae from West Bengal

Pollen morphology of 10 species and 2 varieties of Rhamnacequs taxa belonging to all the four tribes have been worked out. Pollen morphology of the family shows a tendency of evolution from basic morphoforms to the derived ones. Pollen grains of all the taxa investigated have been found to possess triangular or sub-triangular amb with three equatorial apertures situated at the angles (angulo aperturate). In Ziziphus xylopyrus the pollen grains are pororate and in rest nine species those are colporate with circular or lalongate endoapertures. Exinc ornamentation shows a gradual tendency from granulose to rugulo-reticulate or reticulate pattern. Palynological features have been evaluated in understanding the taxonomy of the family.

An Ethnobotanical Study of the Kodavas and other Tribes of Kodagu District, Karnataka

The Kodavas are the original inhabitants of Kodagu at present a district of Karnataka State - located in the Western Ghats. Although Kodavas cannot be classified as tribals under the present conditions, they form a minor ethnic group that has apparently been living amidst the forests of this region over the last few thousand years. Their knowledge of the local plants is extensive, and some of it is recorded here, with a listing of 240 species. These include some 105 medicinal plants, 65 food plants, about 60 timber-yielding plants; some 40 species used in different ways in agriculture and animal husbandry; some 80 species having agricultural and domestic uses, including fibre and fuel plants, those used in cleaning and toiletry, etc; there is some overlapping of usages. Although many of the palnts are well-known, some of the usages are not widely known. Some of the plants merit further investigation and development.

A Revision of the Indian Aponogetonaceae

Unigeneric family Aponogetonaceae, represented by about 44 species of Aponogeton L. f. is distributed in tropics and subtropics of the Old World. The genus Aponogeton is represented by 7 species in India. Detailed taxonomic account including synonymy, morphology, phenology, distribution, ecology, taxonomic note if any, chromosome number and key to the Indian species of Aponogeton is presented in this paper.

Unreported Ethnomedicinal Uses of Plants as Aphrodisiac from the Folk-Lores of Uttar Pradesh Plains, India

The paper deals with unreported medicinal uses of eighteen plant species (belonging to sixteen families) exploited as aphrodisiac among the folk-lores of Uttar Pradesh plains, India. The data are outcome of ethnobotanical survey of more than 300 villages of nine districts viz., Bahraich, Gonda, Hamirpur, Jalaun, Mirzapur, Pratapgarh, Raebareli, Sidharthnagar and Sultanpur. Local name of plant, part of plant used, mode of drug preparation, administration and doses are given under each species.

Ethno-Medicobotanical Survey in Dharwad-Plants Used for Jaundice

Dharwad district is situated at an elevation of 678 m. above MSL. This district is adjacent to Western Ghats. There are several herbal practitioners who depend mostly on the locally available plants. There is no published data on the ethno-medico botanical study of this district and hence an extensive survey was undertaken between 1999-2001. More than 200 traditional herbal practitioners were contacted, amongst whom 54 are effectively treating the jaundice. Twenty five species belonging to 18 families used for curing jaundice in Dharwad district of Karnataka have been recorded. Amongst these species, the most commonly used are Eclipta prostrata L., Plumbago zeylanica L., Ricinus communis L., Balanites aegyptlaca (L) Delile., Phyllanthus niruri L . and Tinospora cordifolia Miers. The method of preparation of medicines disclosed by few of the practitioners are discussed.

The Relationship between Future Wilderness and in Situ and Ex Situ Plant Conservation

Extrapolation of current (1993) rates of wilderness destruction indicate that no significant areas are likely to remain by the year 2300. This likely trend is reinforced by the current continued growth of the human population. The concepts of in situ and ex situ plant species conservation are examined in the context of wilderness loss and practical consequences are discussed including the concept of ad valorem species conservation.

Ethnobotanical Significance of the Flora of Neora Valley National Park in the District of Darjeeling, West Bengal (India)

Recent floristic survey of Neora Valley National Park in Kalimpong sub-division of Darjeeling district of West Bengal revealed that the park is a rich repository of the ethnobotanically important plant resources that includes species of food, medicine, ornamental, poisonous and other assorted ethnic values. Based on available literature and direct interaction with forest dwellers living in the periphery of the park, altogether 83 medicinal, 59 edible, 18 ornamental, 21 poisonous (irritants and lethal) and 11 plants having fascinating assorted ethnic uses have been recognized. The forest dwellers have their own dictionary of local names for the identification of these valuable plant resources by which they are maintaining their own ancient ethnoscience. Many of these medicinal plant species were assessed to be the valuable resources for the treatment of a range of human ailments for which there are no complete answers in the modern medical science (?).

Blue-Green Algal Flora on Archaeological Monuments of India

Forty-six blue-green algal species belonging to fifteen genera, e.g. Gloeocapsopsis, Gloeothece, Myxosarcina, Chroococcidiopsis, Lyngbya, Phromidium, Plectonema, Nostoc, Calothrix, Tolypothrix, Chtorogloeopsis, Fischerella, Hapalosiphon, Westiellopsis and Stigonema occurred on the exposed surfaces of various archaeological monuments from different regions of India. All these blue-green algal species have been isolated and maintained in the culture collection at the Department of Botany, Utkal University.

Some Ethnomedicinal Plants of Dhar District

Dhar district is inhabited by dominating tribes, bhils and bhiialas. Bhils constitute the third largest tribe of India. There are many sub-tribes of bhils viz., tarvi, nayar, nhal, barela, and kotwal. At the same time sub-tribes of bhilalas, darbari bhilala, dhaplya bhilala, rathya bhilala, also live here. They utilize a large number of plant species occurring in wild as herbal remedies on various diseases and ailments in the area. The paper lists 32 such species.

&lt;i&gt;Premna cordifolia&lt;/i&gt; (Verbenaceae) - A Variously Misapplied Name

Premna cordifolia Roxb., does not occur in India. It is found that either this species was misunderstood or the name P. cordifolia misapplied to P. corymbosa Rottler in old literature; or to P. rubens (C.B. Clarke) Ridley in later literature. The species involved are keyed out and their nomenclature is set right. P. rubens is added to the Indian Verbenaceae and the name lectotypified.