Male Deep-Sea Shrimps Aristeus antennatus at Fishing Grounds: Growth and First Evaluation of Recruitment by Multilocus Genotyping

The population biology of the deep-sea shrimp Aristeus antennatus, as with other exploited demersal species, is usually studied using data from fishery statistics. Such statistical analyses have shown female-biased sex ratios during the spawning season in this species. Because the abundance of males increases at greater depths that are not exploited by fisheries (virgin grounds), knowledge on their recruitment is limited. Here, the growth and recruitment of A. antennatus males at fishing grounds was evaluated. This was achieved by integrating information on previously identified breeding behaviours and by tracing the young-of-year cohort through genotyping at 10 microsatellite loci. Using a codend and a codend cover with distinct meshed windows, four groups of males were collected in winter and in a subsequent spawning summer season. Summer collections were mostly composed of pre-adult males, reaching sizes that are to be expected from the growth of winter juveniles; however, many specimens also originated from nearby grounds. This result indicates the horizontal dispersal of male juveniles via intermediate and deep oceanographic currents. Such dispersal complements passive larval dispersal in surface waters, and contributes to the weak genetic divergence among regional fishing grounds. These features could be shared by other deep-sea crustacean and fish species, and should be considered for the sustainable exploitation of demersal fisheries.

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Association between Dyslipidemia and Mercury Exposure in Adults

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18020775 ◽

2021 ◽

Vol 18 (2) ◽

pp. 775

Author(s):

Purum Kang ◽

Hye Young Shin ◽

Ka Young Kim

Keyword(s):

Behavioral Interventions ◽

Dietary Habits ◽

Subjective Health ◽

Targeted Prevention ◽

Adult Males ◽

Subjective Health Status ◽

Factors Affecting ◽

Health And Nutrition ◽

Metal Levels ◽

Using Data

Background—Dyslipidemia is one of the prominent risk factors for cardiovascular disease, which is the leading cause of death worldwide. Dyslipidemia has various causes, including metabolic capacity, genetic problems, physical inactivity, and dietary habits. This study aimed to determine the association between dyslipidemia and exposure to heavy metals in adults. Methods—Using data from the seventh Korean National Health and Nutrition Examination Survey (2016–2017), 5345 participants aged ≥20 years who were tested for heavy metal levels were analyzed in this study. Multiple logistic regression was conducted to assess the factors affecting the prevalence of dyslipidemia. Results—The risks of dyslipidemia among all and male participants with mercury (Hg) levels of ≥2.75 μg/L (corresponding to the Korean average level) were 1.273 and 1.699 times higher than in those with levels of <2.75 μg/L, respectively. The factors that significantly affected the dyslipidemia risk were age, household income, body mass index, and subjective health status in both males and females. Conclusions—In adult males, exposure to Hg at higher-than-average levels was positively associated with dyslipidemia. These results provide a basis for targeted prevention strategies for dyslipidemia using lifestyle guidelines for reducing Hg exposure and healthy behavioral interventions.

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Regional study of microplastics in surface waters and deep sea sediments south of the Algarve Coast

Regional Studies in Marine Science ◽

10.1016/j.rsma.2020.101488 ◽

2020 ◽

Vol 40 ◽

pp. 101488

Author(s):

Simone Lechthaler ◽

Jan Schwarzbauer ◽

Klaus Reicherter ◽

Georg Stauch ◽

Holger Schüttrumpf

Keyword(s):

Surface Waters ◽

Deep Sea ◽

Regional Study ◽

Deep Sea Sediments

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The visual ecology of a deep-sea fish, the escolar Lepidocybium flavobrunneum (Smith, 1843)

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2013.0039 ◽

2014 ◽

Vol 369 (1636) ◽

pp. 20130039 ◽

Cited By ~ 9

Author(s):

Eva Landgren ◽

Kerstin Fritsches ◽

Richard Brill ◽

Eric Warrant

Keyword(s):

Surface Waters ◽

Deep Sea ◽

Ganglion Cells ◽

Optical Path Length ◽

Predatory Fish ◽

Flicker Fusion Frequency ◽

Optical Sensitivity ◽

Light Levels ◽

Electrophysiological Recordings ◽

Maximal Absorption

Escolar ( Lepidocybium flavobrunneum , family Gempylidae) are large and darkly coloured deep-sea predatory fish found in the cold depths (more than 200 m) during the day and in warm surface waters at night. They have large eyes and an overall low density of retinal ganglion cells that endow them with a very high optical sensitivity. Escolar have banked retinae comprising six to eight layers of rods to increase the optical path length for maximal absorption of the incoming light. Their retinae possess two main areae of higher ganglion cell density, one in the ventral retina viewing the dorsal world above (with a moderate acuity of 4.6 cycles deg −1 ), and the second in the temporal retina viewing the frontal world ahead. Electrophysiological recordings of the flicker fusion frequency (FFF) in isolated retinas indicate that escolar have slow vision, with maximal FFF at the highest light levels and temperatures (around 9 Hz at 23°C) which fall to 1–2 Hz in dim light or cooler temperatures. Our results suggest that escolar are slowly moving sit-and-wait predators. In dim, warm surface waters at night, their slow vision, moderate dorsal resolution and highly sensitive eyes may allow them to surprise prey from below that are silhouetted in the downwelling light.

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Trophic state of benthic deep-sea ecosystems from two different continental margins off Iberia

Biogeosciences ◽

10.5194/bg-10-2945-2013 ◽

2013 ◽

Vol 10 (5) ◽

pp. 2945-2957 ◽

Cited By ~ 10

Author(s):

A. Dell'Anno ◽

A. Pusceddu ◽

C. Corinaldesi ◽

M. Canals ◽

S. Heussner ◽

...

Keyword(s):

Organic Matter ◽

Water Depth ◽

Surface Waters ◽

Deep Sea ◽

Nutritional Value ◽

Trophic State ◽

Phytoplankton Bloom ◽

Continental Margins ◽

Organic C ◽

Deep Sea Sediments

Abstract. The bioavailability of organic matter in benthic deep-sea ecosystems, commonly used to define their trophic state, can greatly influence key ecological processes such as biomass production and nutrient cycling. Here, we assess the trophic state of deep-sea sediments from open slopes and canyons of the Catalan (NW Mediterranean) and Portuguese (NE Atlantic) continental margins, offshore east and west Iberia, respectively, by using a biomimetic approach based on enzymatic digestion of protein and carbohydrate pools. Patterns of sediment trophic state were analyzed in relation to increasing water depth, including repeated samplings over a 3 yr period in the Catalan margin. Two out of the three sampling periods occurred a few months after dense shelf water cascading events. The benthic deep-sea ecosystems investigated in this study were characterized by high amounts of bioavailable organic matter when compared to other deep-sea sediments. Bioavailable organic matter and its nutritional value were significantly higher in the Portuguese margin than in the Catalan margin, thus reflecting differences in primary productivity of surface waters reported for the two regions. Similarly, sediments of the Catalan margin were characterized by significantly higher food quantity and quality in spring, when the phytoplankton bloom occurs in surface waters, than in summer and autumn. Differences in the benthic trophic state of canyons against open slopes were more evident in the Portuguese than in the Catalan margin. In both continental margins, bioavailable organic C concentrations did not vary or increase with increasing water depth. Overall, our findings suggest that the intensity of primary production processes along with the lateral transfer of organic particles, even amplified by episodic events, can have a role in controlling the quantity and distribution of bioavailable organic detritus and its nutritional value along these continental margin ecosystems.

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