Morfología del sistema reproductor y del espermatóforo de Litopenaeus vannamei, camarón blanco del Pacífico

In order to advance in the knowledge of the male reproductive system of Litopanaeus vannamei, the anatomical description of its reproductive system in sexually mature animals was performed. Animals were obtained from a Mexican shrimp hatchery, located in Sinaloa, Mexico. To describe the anatomy, a) 8 male reproductive systems were removed; b) 10 spermatophores compounds were extracted from naturally inseminated females; and c) 40 sperm sacs derived from the right and the left ampulla were manually extracted. In general, the reproductive system was found similar to the observed in other species of the genus Penaeus. However, differences in the shape of the testes and of the terminal ampulla that are characteristic of this species were observed. An area located between the anterior vas deferens and the middle duct, known in other species as blind pouch, was observed. The compound spermatophore is a structure that has been described anatomically, although when freshly extracted it is difficult to observe because the type of substances that compose it and because of the morphological changes introduced when it contacts water. In each sperm sac of the spermatophore, sperm chamber is located from its medial to its distal part, with the highest concentration of sperm in the distal region.Con el objetivo de aportar información al conocimiento del sistema reproductor en machos de Litopenaeus vannamei, se elaboró la descripción anatómica de su sistema reproductor, empleando para ello machos sexualmente maduros, obtenidos de un laboratorio productor de larvas ubicado en Sinaloa, México. Para hacer la descripción, se obtuvieron por disección: a) los órganos reproductores completos de 8 machos; b) 10 espermatóforos compuestos que fueron extraídos de hembras inseminadas naturalmente; y c) 40 sacos espermáticos extraídos manualmente de las ámpulas derecha e izquierda. El sistema reproductor se asemeja al de otras especies del género Penaeus, sin embargo, posee diferencias en la forma de los testículos y del ámpula terminal, que lo hace característico de esta especie. También se localizó un área diferenciada entre el conducto deferente anterior y el conducto deferente medio que ha sido denominada en otras especies como saco ciego. El espermatóforo compuesto es una estructura que ha sido descrita anatómicamente, aunque su observación en fresco es difícil de realizar por el tipo de sustancias que lo forman y los cambios morfológicos que presenta al tener contacto con el agua. En cada uno de las sacos espermáticos del espermatóforo, la cámara espermática abarca desde la parte media hasta la parte distal del mismo, encontrándose la mayor concentración de espermatozoides en la región distal

EARLINET instrument intercomparison campaigns: Overview on strategy and results

This paper introduces the recent European Aerosol Research Lidar Network (EARLINET) quality-assurance efforts at instrument level. Within two dedicated campaigns and five single-site intercomparison activities, 21 EARLINET systems from 18 EARLINET stations were intercompared between 2009 and 2013. A comprehensive strategy for campaign setup and data evaluation has been established. Eleven systems from nine EARLINET stations participated in the EARLINET Lidar Intercomparison 2009 (EARLI09). In this campaign, three reference systems were qualified which served as traveling standards thereafter. EARLINET systems from nine other stations have been compared against these reference systems since 2009. We present and discuss comparisons at signal and at product level from all campaigns for more than 100 individual measurement channels at the wavelengths of 355, 387, 532, and 607 nm. It is shown that in most cases, a very good agreement of the compared systems with the respective reference is obtained. Mean signal deviations in predefined height ranges are typically below ±2 %. Particle backscatter and extinction coefficients agree within ±2  ×  10−4 km−1 sr−1 and ± 0.01 km−1, respectively, in most cases. For systems or channels that showed larger discrepancies, an in-depth analysis of deficiencies was performed and technical solutions and upgrades were proposed and realized. The intercomparisons have reinforced confidence in the EARLINET data quality and allowed us to draw conclusions on necessary system improvements for some instruments and to identify major challenges that need to be tackled in the future

Susceptibility of Litopenaeus schmitti and Cherax quadricarinatus to white spot syndrome virus (WSSV)

 Bioassays were carried out in a closed system to evaluate the susceptibility of Litopenaeus schmitti and Cherax quadricarinatus to white spot syndrome virus (WSSV) using L. vannamei as the positive control reference species. Animals were injected intramuscularly (20 ∞L shrimp–1) with a WSSV preparation obtained from the Aquaculture Pathology Laboratory of the University of Arizona. These infected organisms were reared separately in their respective experimental tank. Susceptibility to WSSV was significantly greater in L. vannamei than in the other two species (P < 0.05). The histological analysis showed characteristic inclusion bodies of WSSV in these three crustacean species, with a different distribution of infection depending on the tissue and species. In situ hybridization also showed these signs of infection in hemocytes and hepatopancreas

Feeding Behavior, Shrinking, and the Role of Mucus in the Cannonball Jellyfish <i>Stomolophus</i> sp. 2 in Captivity

The importance of mucus produced by jellyfish species remains as understudied as their feeding behavior. Here, we study medusae under captivity, ascertain the role of mucus, and describe its feeding behavior. Between February and March 2019, live adult cannonball jellyfish, Stomolophus sp. 2, were collected in Las Guásimas Bay (Gulf of California, Mexico) and were offered fish eggs, mollusk “D” larvae, or Artemia nauplii in 4-day trials. Descriptions of feeding structures were provided for S. sp. 2. Digitata adhere food and scapulets fragment them, which, driven by water flow, pass via transport channels to the esophagus and the gastrovascular chamber where food is digested. Due to stress by handling, medusae produced mucus and water, lost feeding structures, and decreased in size. Based on our observations and a thorough literature review, we conclude that the production of mucus in S. sp. 2 plays several roles, facilitating capture and packing of prey, acting as a defense mechanism, and facilitating sexual reproduction; the latter improves the likelihood of a population persisting in the long run, because fertilized oocytes in mucus transform to planulae, settle, and transform into asexually reproducing polyps. Polyps live longer than the other life stages and are more resistant to adverse environmental conditions than the medusoid sexual stage

EARLINET correlative measurements for CALIPSO: First intercomparison results

A strategy for European Aerosol Research Lidar Network (EARLINET) correlative measurements for Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) has been developed. These EARLINET correlative measurements started in June 2006 and are still in progress. Up to now, more than 4500 correlative files are available in the EARLINET database. Independent extinction and backscatter measurements carried out at high-performance EARLINET stations have been used for a quantitative comparison with CALIPSO level 1 data. Results demonstrate the good performance of CALIPSO and the absence of evident biases in the CALIPSO raw signals. The agreement is also good for the distribution of the differences for the attenuated backscatter at 532 nm ((CALIPSO-EARLINET)/EARLINET (%)), calculated in the 1-10 km altitude range, with a mean relative difference of 4.6%, a standard deviation of 50%, and a median value of 0.6%. A major Saharan dust outbreak lasting from 26 to 31 May 2008 has been used as a case study for showing first results in terms of comparison with CALIPSO level 2 data. A statistical analysis of dust properties, in terms of intensive optical properties (lidar ratios, Ångström exponents, and color ratios), has been performed for this observational period. We obtained typical lidar ratios of the dust event of 49 ± 10 sr and 56 ± 7 sr at 355 and 532 nm, respectively. The extinction-related and backscatter-related Ångström exponents were on the order of 0.15-0.17, which corresponds to respective color ratios of 0.91-0.95. This dust event has been used to show the methodology used for the investigation of spatial and temporal representativeness of measurements with polar-orbiting satellites. Copyright 2010 by the American Geophysical Union

Earlinet instrument intercomparison campaigns: overview on strategy and results

This paper introduces the recent European Aerosol Research Lidar Network (EARLINET) quality-assurance efforts at instrument level. Within two dedicated campaigns and five single-site intercomparison activities, 21 EARLINET systems from 18 EARLINET stations were intercompared between 2009 and 2013. A comprehensive strategy for campaign setup and data evaluation has been established. Eleven systems from nine EARLINET stations participated in the EARLINET Lidar Intercomparison 2009 (EARLI09). In this campaign, three reference systems were qualified which served as traveling standards thereafter. EARLINET systems from nine other stations have been compared against these reference systems since 2009. We present and discuss comparisons at signal and at product level from all campaigns for more than 100 individual measurement channels at the wavelengths of 355, 387, 532, and 607 nm. It is shown that in most cases, a very good agreement of the compared systems with the respective reference is obtained. Mean signal deviations in predefined height ranges are typically below +/- 2 %. Particle backscatter and extinction coefficients agree within +/- 2 x 10(-4) km(-1) sr(-1) and +/- 0.01 km(-1), respectively, in most cases. For systems or channels that showed larger discrepancies, an in-depth analysis of deficiencies was performed and technical solutions and upgrades were proposed and realized. The intercomparisons have reinforced confidence in the EARLINET data quality and allowed us to draw conclusions on necessary system improvements for some instruments and to identify major challenges that need to be tackled in the future

EARLINET all observations (2000-2010)

This collection contains all measurements that have been performed in the frame of the EARLINET project during the period April 2000 - December 2010. Some of these measurements are also part of the collections 'Calipso', 'Climatology', 'SaharanDust' or 'VolcanicEruption'. In addition this collection also contains measurements from the categories 'Cirrus', 'DiurnalCycles', 'ForrestFires', 'Photosmog', 'RuralUrban', and 'Stratosphere'. This collection also contains measurements not devoted to any of the above categories. More information about these categories and the contributing stations can be found in the file 'EARLINET_general_introduction.pdf' accompanying this dataset