Morphological variations of Phrosina semilunata Risso, 1822 juveniles (Crustacea: Amphipoda: Hyperiidea), new evidence from the Gulf of Mexico

Zootaxa ◽  
2021 ◽  
Vol 4995 (3) ◽  
pp. 594-600
Author(s):  
MARCO VIOLANTE-HUERTA ◽  
LAURA SANVICENTE-AÑORVE ◽  
MARGARITA HERMOSO-SALAZAR ◽  
AURORA MARRÓN-BECERRA

Lack of knowledge of morphological variations during growth of amphipod crustaceans can result in misidentification of species. In this study, we advance the knowledge of morphological variations of juveniles of the monotypic genus Phrosina Risso, 1822 collected in the oceanic province of the southern Gulf of Mexico. The juveniles differed from the adults mainly in the morphology of pereopods 3 & 4 in that the carpal process is parallel to the propodus, also the rami of the pleopoda consist of only four segments, uropoda 3 are more lanceolate, and the uropoda bear a large prominent spine terminally. These morphological variations have not been described for the species previously. Therefore, the current observations enrich the description of P. semilunata in the early stages of growth and support the need for further taxonomical studiest that could help identify species at different stages of development.  

Author(s):  
M. Orlovskyi ◽  
◽  
A. Kosiuk ◽  
A. Ishchuk ◽  
V. Voitsekhivskyi ◽  
...  

The results of research on the effect of pre-sowing treatment of seeds and plants with Vimpel-2, Oracle multicomplex, Oracle zinc separately and together in different phases of maize plants of the early hybrid DN Meotida are presented. The research was conducted by us in the field conditions of Khmelnytsky SARS IFAP NAAS of Ukraine (2018-2020). As a result of the conducted researches the following conclusions are made. The combination of pre-sowing treatment of seeds with subsequent treatment of corn crops in the early stages of development of the complex of drugs provided an increase in height of corn plants, corn plant height increased, on average over the years by 26,0 cm or 11,5%, leaf surface area by 0,075 m2 or 23,5%. All studied variants of pre-sowing seed treatment and foliar fertilization provided an increase in the number of productive cobs, compared to the control, by 2-9 pcs. or 2-9 % - on average over the years of research. All studied methods of pre-sowing seed treatment and foliar feeding of corn in the early stages of growth provided an increase, on average over the years of research, the weight of grain from 1 head of corn by 9,0-29,2 g or 7,8-25,5%, weight gain 1000 grains - by 18,0-29,3 g or 6,8-11,2% compared to the control. All studied methods of pre-sowing seed treatment and foliar feeding of maize plants in the early stages of development provided a significant increase in grain yield compared to control – 0,65-1,62 t / ha or 9,1-22,6%, on average for two years of research.


Author(s):  
George G. Cocks ◽  
Louis Leibovitz ◽  
DoSuk D. Lee

Our understanding of the structure and the formation of inorganic minerals in the bivalve shells has been considerably advanced by the use of electron microscope. However, very little is known about the ultrastructure of valves in the larval stage of the oysters. The present study examines the developmental changes which occur between the time of conception to the early stages of Dissoconch in the Crassostrea virginica(Gmelin), focusing on the initial deposition of inorganic crystals by the oysters.The spawning was induced by elevating the temperature of the seawater where the adult oysters were conditioned. The eggs and sperm were collected separately, then immediately mixed for the fertilizations to occur. Fertilized animals were kept in the incubator where various stages of development were stopped and observed. The detailed analysis of the early stages of growth showed that CaCO3 crystals(aragonite), with orthorhombic crystal structure, are deposited as early as gastrula stage(Figuresla-b). The next stage in development, the prodissoconch, revealed that the crystal orientation is in the form of spherulites.


2021 ◽  
Vol 9 (8) ◽  
pp. 793
Author(s):  
Abigail Uribe-Martínez ◽  
María de los Angeles Liceaga-Correa ◽  
Eduardo Cuevas

Marine turtles are globally endangered species that spend more than 95% of their life cycle in in-water habitats. Nevertheless, most of the conservation, recovery and research efforts have targeted the on-land habitats, due to their easier access, where adult females lay their eggs. Targeting the large knowledge gaps on the in-water critical habitats of turtles, particularly in the Large Marine Ecosystem Gulf of Mexico, is crucial for their conservation and recovery in the long term. We used satellite telemetry to track 85 nesting females from their beaches after they nested to identify their feeding and residency habitats, their migratory corridors and to describe the context for those areas. We delimited major migratory corridors in the southern Gulf of Mexico and West Caribbean and described physical features of internesting and feeding home ranges located mainly around the Yucatan Peninsula and Veracruz, Mexico. We also contributed by describing general aggregation and movement patterns for the four marine turtle species in the Atlantic, expanding the knowledge of the studied species. Several tracked individuals emigrated from the Gulf of Mexico to as far as Nicaragua, Honduras, and the Bahamas. This information is critical for identifying gaps in marine protection and for deciphering the spatial connectivity in large ocean basins, and it provides an opportunity to assess potential impacts on marine turtle populations and their habitats.


2019 ◽  
Vol 13 ◽  
pp. 04020
Author(s):  
Giovan Battista Mattii ◽  
Eleonora Cataldo ◽  
Linda Salvi ◽  
Sofia Sbraci ◽  
Francesca Paoli ◽  
...  

In the early stages of planting, the shelter can provide for young vines protection against damage of various kinds. Despite their widespread use, few surveys have been devoted to the study of innovative shelter types and the possible influence of these protections on the physiology and development of plants. In the present experiment, which took place in 2017 in a Tuscan winery, the effects of vine protections by the company OSO (Prato) on single leaf gas exchanges and on the shoot growth in the first year of planting were studied. Three types of shelters with a circular section (completely perforated, partially perforated and closed) have been compared with the traditional full-wall shelters with square section. During the growing season, sprout growth measures, leaf area, leaf gas exchanges and water potential were carried out on the young vines. At the end of the season, shoots were sampled to measure the dry matter accumulated during the season. Among the shelters taken into consideration, it emerges that the completely perforated type guarantees the best development, with differences that are almost always significant for most of the measured parameters with traditional shelters. On the contrary, the closed typology has led to a reduction in growth, in gas exchanges and in water potential. In conclusion, the type completely perforated could constitute a valid alternative to the traditional one because, besides being a useful means for the protection of the vine, it could benefit the development of the root system in the early stages of growth.


2016 ◽  
Vol 21 (3) ◽  
pp. 279-286 ◽  
Author(s):  
Fatemeh Nasibi ◽  
Khosrow Manouchehri Kalantari ◽  
Roya Zanganeh ◽  
Ghasem Mohammadinejad ◽  
Hakimeh Oloumi

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