Supplement 1. Stereo drop camera descriptionThe two stereo drop camera systems were comprised of two machine-vision cameras spaced approximately 30 cm apart in underwater housings that were connected via ethernet cables to a computer also in an underwater housing. On the first drop-camera system, one of the paired cameras recorded monochromatic still images sized at 1.45 megapixels (JAI, CM-140GE), while the other camera collected 1.73 megapixel color still images (JAI, AB-201GE). On the second drop-camera system, one of the paired cameras recorded monochromatic still images sized at 1.45 megapixels (JAI, CM-140GE), while the other camera collected 2.82 megapixel color still images (Prosilica GX 1920C). Lighting was provided by four strobe lights constructed of four Bridgelux® BXRA LED arrays capable of producing 1,300 lumens at 10.4 W. The computer, cameras, and lights were powered by a 28 V NiMH battery pack. Synchronous images were collected and recorded from each of the cameras at a frequency of one image per second. Each of the systems was enclosed in an aluminum cage to protect the components from damage. Additionally, a 1/4 inch diameter coaxial cable provided a connection from the drop-camera system to the winch at the surface, allowing images from the monochrome camera were viewed in real time at a rate of four images per second. This allowed the height of the camera to be actively controlled to keep it just above the seafloor using a quick response electric winch. Supplement 2. Distribution modeling of structure forming invertebrates and cross-validation using bottom trawl survey and camera survey data Bottom trawl survey modelsThe initial distribution modeling was carried out using bottom trawl survey data collected on the NOAA Fisheries, Alaska Fisheries Science Center, eastern Bering Sea outer shelf and slope surveys from 2002 to 2012 and was reported in Sigler et al. (2015). Briefly, the invertebrate distributions were predicted using generalized additive models (GAM) to determine the relationships between environmental variables (latitude*longitude, depth, slope, long-term average bottom temperature, ocean color, mean current speed, maximum tidal current speed, sediment grain size and sediment sorting which is the standard deviation of grain size) and observations of presence in bottom trawl survey catches for each structure-forming invertebrate group. All modeling was carried out in R software using the mgcv package (Wood 2006) and diagnostics were performed using the PresenceAbsence package. A binomial distribution was used to model presence or absence data and backwards term selection was employed so that the full model including all variables was fit first and
Blood culture is a diagnostic tool used in confirming bacterial disease in teleostean and elasmobranch fishes. Unlike teleosts, elasmobranchs have a normal microflora in multiple organs, but their blood has generally been considered to be sterile. In regular exams of elasmobranchs conducted at a public aquarium, occasional blood samples have tested positive on culture. This finding prompted a blood culture survey of healthy captive and wild elasmobranchs (sharks and stingrays), which showed that 26.7% of all animals were positive. Stingrays alone showed a 50% occurrence of positive blood cultures, although the total number of animals was low and freshwater species were included in this number. When elasmobranchs other than stingrays were evaluated according to metabolic category, pelagic animals had a higher percentage of positive cultures than nonpelagic animals (38.7% versus 13.9%). These results indicate that a single positive blood culture without other corroborating diagnostics is not sufficient to confirm septicemia in elasmobranchs.
Brevity of handling or chemical restraint may have reduced secondary stress responses in fish because extreme variations in blood analyte values were infrequent. Sample collection site, species categorization, acclimation to handling, and restraint technique should be considered when assessing values obtained with the POC analyzer used in this study for blood analytes and immediate metabolic status in elasmobranchs.
T he field of elasmobranch medicine is in its infancy, and there is a paucity of information on hematologic values 1-4 despite the growing need for veterinary care of cap-tive sharks. Sites for collection of blood samples in sharks are typically chosen in accordance with the method of animal handling. When a shark is large or difficult to manually restrain, it is most convenient to obtain a blood sample from the dorsal sinus, an area located at the caudal aspect at the base of the dorsal fin. This method allows handlers to maintain the shark in ventral recumbency. When a shark is easily restrained or anesthetized, blood collection from the caudal tail vein or artery is usually chosen because the shark can be placed in dorsal recumbency, which facilitates access to the vessels. In the authors' clinical experience, Hcts differ in samples collected from these 2 sites for use in routine health screening of captive shark populations. To assess the importance of this observation, a prospective study was initiated that used both captive habituated sharks and captured free-ranging (wild) sharks.Sharks can be classified into metabolic categories on the basis of their method of respiration. Pelagic sharks (ie, open-water sharks) rely on ram ventilation. These sharks ensure ventilation by forcing water over their gills and, hence, are obligated to swim constantly. Conversely, nonpelagic sharks (ie, reef-oriented species of sharks) are capable of pumping water over their gills and can rest on the ocean bottom for extended periods. The nonpelagic species have a higher tolerance for anaerobic situations than do the pelagic sharks. 5,6 The Hct in tuna, a high-energy, ram-ventilating teleost, is considerably higher than the Hct in most other teleosts because tuna have a high requirement for oxygen. 7 Therefore, we elected to assess whether similar differences existed in pelagic and nonpelagic sharks. Materials and MethodsAnimals-Blood samples were collected from 47 adult sharks. The sharks comprised 2 groups (32 captive habituated sharks and 15 captured free-ranging wild sharks). Sharks were considered adults on the basis of secondary sex characteristics; standard and total length measurements; and, when possible, body weight.Collection of blood samples-Captive habituated adult sharks were acclimated to captive conditions for at least 1 year, and all were handled or anesthetized during that time period. Samples were obtained twice from some sharks. Animals included 4 brown sharks (Carcharhinus plumbeus), 13 blacktip reef sharks (Carcharhinus melanopterus), 3 wobegong sharks (Orectolobus japonicus), 4 zebra sharks (Stegastoma fasciatum), and 8 whitetip reef sharks (Triaenodon obesus). All sharks were considered healthy on the basis of results of physical examination, routine hematologic tests, and serum biochemical analysis, as determined by use of in-house reference ranges.Objective-To evaluate differences in Hct between 2 venipuncture sites in captive and free-ranging sharks. Animals-32 healthy adult captive sharks (Carcharhinu...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.