Revolutions in rearing barnacles: rotating flow and substratum for culturing larvae and adults

2020 ◽  
Author(s):  
John D Zardus ◽  
Zachary M Lane
Keyword(s):  
Larval Stage ◽  
Sea Turtles ◽  
Rotating Flow ◽  
Mobile Homes ◽  
Dynamic Surfaces ◽  
Dual Stage ◽  
Marine Megafauna

Barnacles that live attached to dynamic surfaces, particularly species that are epizoic with marine megafauna, draw benefit from their mobile homes through assistance with passive feeding and escape from predators. A moveable substratum may also offer positive cues for their settling larvae. In this study, we tested a technique for rearing in the laboratory, from larval stage to adult, a barnacle that associates with sea turtles, Chelonibia testudinaria. A dual-stage culturing system was devised, coupling circular tanks with rotating substrata to generate effects of flow and motion. A round-bottomed culturing vessel with gentle cyclical flow was used to raise larvae and then induce them to settle on revolving PVC pipes. The colonized pipes were then transferred to a separate tank for grow-out with continued rotation. Though settlement rates were low, the system proved valuable in obtaining the even distribution of a satisfactory number of juveniles across the pipes and in growing them in the laboratory for up to two years. This technique opens a variety of avenues of study for taxa that prefer or require a dynamic substratum.

scholarly journals Incorporating Geographical Scale and Multiple Environmental Factors to Delineate the Breeding Distribution of Sea Turtles

Drones ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 142
Author(s):  
Liam C. Dickson ◽  
Kostas A. Katselidis ◽  
Christophe Eizaguirre ◽  
Gail Schofield
Keyword(s):  
Sea Turtles ◽  
Regional Distribution ◽  
Environmental Parameters ◽  
Environmental Data ◽  
Offshore Wind ◽  
Loggerhead Sea Turtles ◽  
Change Models ◽  
Terrestrial Environments ◽  
Aircraft System ◽  
Marine Megafauna

Temperature is often used to infer how climate influences wildlife distributions; yet, other parameters also contribute, separately and combined, with effects varying across geographical scales. Here, we used an unoccupied aircraft system to explore how environmental parameters affect the regional distribution of the terrestrial and marine breeding habitats of threatened loggerhead sea turtles (Caretta caretta). Surveys spanned four years and ~620 km coastline of western Greece, encompassing low (<10 nests/km) to high (100–500 nests/km) density nesting areas. We recorded 2395 tracks left by turtles on beaches and 1928 turtles occupying waters adjacent to these beaches. Variation in beach track and inwater turtle densities was explained by temperature, offshore prevailing wind, and physical marine and terrestrial factors combined. The highest beach-track densities (400 tracks/km) occurred on beaches with steep slopes and higher sand temperatures, sheltered from prevailing offshore winds. The highest inwater turtle densities (270 turtles/km) occurred over submerged sandbanks, with warmer sea temperatures associated with offshore wind. Most turtles (90%) occurred over nearshore submerged sandbanks within 10 km of beaches supporting the highest track densities, showing the strong linkage between optimal marine and terrestrial environments for breeding. Our findings demonstrate the utility of UASs in surveying marine megafauna and environmental data at large scales and the importance of integrating multiple factors in climate change models to predict species distributions.

scholarly journals Revealing Sea Turtle Behavior in Relation to Fishing Gear Using Color-Coded Spatiotemporal Motion Patterns With Deep Neural Networks

2021 ◽  
Vol 8 ◽  
Author(s):  
Janie L. Reavis ◽  
H. Seckin Demir ◽  
Blair E. Witherington ◽  
Michael J. Bresette ◽  
Jennifer Blain Christen ◽  
...  
Keyword(s):  
Sea Turtles ◽  
Marine Species ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Time Frame ◽  
Visual Object ◽  
Fishing Gear ◽  
Motion Patterns ◽  
Incidental Capture ◽  
Marine Megafauna

Incidental capture, or bycatch, of marine species is a global conservation concern. Interactions with fishing gear can cause mortality in air-breathing marine megafauna, including sea turtles. Despite this, interactions between sea turtles and fishing gear—from a behavior standpoint—are not sufficiently documented or described in the literature. Understanding sea turtle behavior in relation to fishing gear is key to discovering how they become entangled or entrapped in gear. This information can also be used to reduce fisheries interactions. However, recording and analyzing these behaviors is difficult and time intensive. In this study, we present a machine learning-based sea turtle behavior recognition scheme. The proposed method utilizes visual object tracking and orientation estimation tasks to extract important features that are used for recognizing behaviors of interest with green turtles (Chelonia mydas) as the study subject. Then, these features are combined in a color-coded feature image that represents the turtle behaviors occurring in a limited time frame. These spatiotemporal feature images are used along a deep convolutional neural network model to recognize the desired behaviors, specifically evasive behaviors which we have labeled “reversal” and “U-turn.” Experimental results show that the proposed method achieves an average F1 score of 85% in recognizing the target behavior patterns. This method is intended to be a tool for discovering why sea turtles become entangled in gillnet fishing gear.

scholarly journals Pilot aerial study of the marine megafauna in northern coast Alagoas, Brazil

2013 ◽  
Vol 41 (1-2) ◽  
Author(s):  
Maria Danise de Oliveira ALVES ◽  
João Carlos Gomes BORGES ◽  
Maria Elisabeth De ARAÚJO
Keyword(s):  
Sea Turtles ◽  
Water Clarity ◽  
Aerial Survey ◽  
Northern Coast ◽  
Sampling Area ◽  
Turbid Waters ◽  
Aerial Surveys ◽  
Low Visibility ◽  
Marine Megafauna ◽  
Strip Transect

This study aimed to investigate the feasibility of strip-transect aerial survey for the study of the marine megafauna in northern coast of Alagoas, chosen as the pilot area due to the better water clarity and the occurrence of the Antillean manatee. It was sighted 15 dolphins, 13 sea turtles and 10 manatees. From five aspects tested on the experimental flight, three adjustments were necessary on the methodology as following: 1) reduction of the transect angle to 40º to increase the sampling area; 2) constant transects of 1.5 nautical miles from shore to standardize the area of coverage; and 3) transects restricted to the mouths of estuaries due to low visibility in turbid waters. This study demonstrated the effectiveness of aerial surveys for the detection of marine megafauna. However, the adjustments proposed are necessary to minimize the characteristic limitations of each species and/or habitat. Keywords: aerial method, manatees, dolphins, sea turtles, limitations

Marine Megafauna Sea Turtles, Seabirds and Marine Mammals

2021 ◽  
pp. 297-324
Author(s):  
Rocío Mariano Jelicich ◽  
Paula Berón ◽  
Sofia Copello ◽  
Natalia A. Dellabianca ◽  
Germán García ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Sea Turtles ◽  
Marine Megafauna

The early development of antenna and antennal sensilla in the noctuid moth, Agrotis segetum (Insecta: Lepidoptera)

1990 ◽  
Vol 48 (3) ◽  
pp. 502-503
Author(s):  
Eric Hallberg ◽  
Lina Hansén
Keyword(s):  
Cell Death ◽  
Stem Cell ◽  
Early Development ◽  
Larval Stage ◽  
Pupal Stage ◽  
Agrotis Segetum ◽  
Antennal Sensilla ◽  
Noctuid Moth ◽  
Standard Procedures

The antennal rudiments in lepidopterous insects are present as disks during the larval stage. The tubular double-walled antennal disk is present beneath the larval antenna, and its inner layer gives rise to the adult antenna during the pupal stage. The sensilla develop from a cluster of cells that are derived from one stem cell, which gives rise to both sensory and enveloping cells. During the morphogenesis of the sensillum these cells undergo major transformations, including cell death. In the moth Agrotis segetum the pupal stage lasts about 14 days (temperature, 25°C). The antennae, clearly seen from the exterior, were dissected and fixed according to standard procedures (3 % glutaraldehyde in 0.15 M cacaodylate buffer, followed by 1 % osmiumtetroxide in the same buffer). Pupae from day 1 to day 8, of both sexes were studied.

INTERACTIONS BETWEEN CYSTICERCUS FASCIOLARIS AND COMMON RATS

2017 ◽  
Vol 23 (2) ◽  
Author(s):  
SHASHI KIRAN
Keyword(s):  
Granulation Tissue ◽  
Larval Stage ◽  
Histopathological Examination ◽  
Sylvatic Cycle ◽  
Mature Larva ◽  
Hepatic Cysts ◽  
Cysticercus Fasciolaris ◽  
Taenia Taeniaeformis ◽  
Relationship Of ◽  
The Relationship

The objective of this study was to determine the relationship of C. fasciolaris with common rats. Cysticercus fasciolaris is the larval stage of Taenia taeniaeformis . Development of metacestodes ( Cysticercus fasciolaris) occur in the liver of rodents. An urban and a sylvatic cycle occurs. A total of 40 liver specimens of rats were examined. Histopathological examination revealed the presence of multiple hepatic cysts, and the C. fasciolaris larva was surrounded by granulation tissue. Large and separated ûbroblasts in different orientations with some neoplastic changes were seen in advanced hepatic cysticercosis. The bladder involved the larva and large chamber containing the small chamber and opalescent fluid. The scolex of the mature larva is distinctly large, bearing four lateral distinct suckers, a rostellum armed with double, and alternating rows of hooks.

Presence of chelonid herpesvirus 5 (ChHV5) in sea turtles in northern Sinaloa, Mexico

2019 ◽  
Vol 132 (2) ◽  
pp. 99-108
Author(s):  
RY Mejía-Radillo ◽  
AA Zavala-Norzagaray ◽  
JA Chávez-Medina ◽  
AA Aguirre ◽  
CM Escobedo-Bonilla
Keyword(s):  
Sea Turtles
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