scholarly journals ON THE DISCOVERY OF A LARGE MICROBIAL COMMUNITY LIVING IN THE SOFT BOTTOMS OF THE CONTINENTAL SHELF OFF CHILE AND PERU

2016 ◽  
Vol 1 ◽  
Author(s):  
Víctor A. Gallardo
Keyword(s):  
Continental Shelf ◽  
Northern Chile ◽  
Ecological Significance ◽  
Low Oxygen ◽  
Central Chile ◽  
Average Biomass ◽  
Soft Bottoms ◽  
Wet Weight ◽  
Commercially Important ◽  
Filamentous Material

In a benthic macrofaunal survey of the continental shelf of northern Chile a peculiar filamentous material was collected in grab and dredge samples of greenish, foul smelling sediment from depths of 50 to 280 m (ref. 1). In reporting the results emphasis was placed, however, on the fact that a virtually iazoic* bottom had beenfound between depths of 50 to 400 m. Average biomass was only 0.17 g (wet weight) /m2 , with 6.6 individuals /m2*. The distribution of the azoic sediments coincided with low oxygen concentrations in the water above (ref. 2). The author again found white filamentous material while sampling the benthos off the Bay of Concepcion and the Gulf of Arauco, in central Chile. These findings together with the casual observation of filaments in the mouth parts of the commercially important galatheid shrimp Pleuroncodes mondon, initiated new efforts to learn about this material and its possible ecological significance.

Aerobic and anaerobic metabolism of Paraprionospio pinnata (Polychaeta: Spionidae) in central Chile

2007 ◽  
Vol 87 (2) ◽  
pp. 459-463 ◽  
Author(s):  
Eduardo Quiroga ◽  
Renato A. Quiñones ◽  
Rodrigo R. González ◽  
Victor A. Gallardo ◽  
Gerdhard Jessen
Keyword(s):  
Anaerobic Metabolism ◽  
Dry Weight ◽  
Aerobic Respiration ◽  
Low Oxygen ◽  
Central Chile ◽  
Respiration Rates ◽  
Laboratory Conditions ◽  
Hypoxic Conditions ◽  
Wet Weight ◽  
Aerobic And Anaerobic

The aerobic and anaerobic metabolism of Paraprionospio pinnata were estimated under laboratory conditions. Paraprionospio pinnata is a widely distributed, often dominant polychaete inhabiting sublittoral sediments on the continental shelf off central Chile, where there is a pronounced oxygen minimum zone (OMZ). The aerobic respiration rates ranged from 0.25 to 1.28 ml O2 h-1 g-1 dry weight. Paraprionospio pinnata displayed oxyconformity between 30 mm Hg (4 kPa) and 104 mm Hg (14 kPa) of oxygen tension levels (pO2) under laboratory conditions. We found that P. pinnata is an aerobic oxygen conformer and is able to endure very low oxygen conditions. High anaerobic activity of alanopine dehydrogenase (5.74 ±1.20 μmol NADH min-1 g-1 wet weight) and strombine dehydrogenase (8.82 ±4.04 μmol NADH min-1 g-1 wet weight) were observed. The ratio between the calculated aerobic respiration rates and the electron transfer system activity were 0.28 and 0.12 for normoxic and hypoxic conditions, respectively. Based on the observed respiration rates and the average densities of P. pinnata in the study site, we estimated the population carbon flux via aerobic respiration to be about 32 mg C m-2 d-1 in spring and 80 mg C m-2 d-1 in winter. Paraprionospio pinnata would be using, then, about 8.6% of the total downward flux of organic carbon to the seabed and contributing between 18 and 44% of the total sediment community oxygen consumption.

scholarly journals Novel Comprehensive Molecular and Ecological Study Introducing Coastal Mud Shrimp (Solenocera Crassicornis) Recorded at the Gulf of Suez, Egypt

2020 ◽  
Vol 9 (1) ◽  
pp. 9
Author(s):  
Eman M. Abbas ◽  
Fawzia S. Ali ◽  
Mohammed G. Desouky ◽  
Mohamed Ashour ◽  
Ahmed El-Shafei ◽  
...  
Keyword(s):  
Molecular Identification ◽  
Phylogenetic Relationships ◽  
Genetic Distances ◽  
Larval Rearing ◽  
Gulf Of Suez ◽  
Commercial Catch ◽  
Monthly Total ◽  
Wet Weight ◽  
Commercially Important ◽  
The Relationship

Solenocera crassicornis is a commercially important shrimp of the Solenoceridae family. The current study investigated the morphology, molecular identification, phylogenetic relationships, and population dynamics of S. crassicornis in Egypt. Samples were collected monthly (total, 1722; male = 40.19%, wet weight, 0.89–10.77 g; female = 59.81%, wet weight, 1.55–19.24 g) from Al-Attaka commercial catch in the Gulf of Suez in the Red Sea. Two barcode markers, 18S rRNA and cytochrome c oxidase subunit I (COI), were used for molecular identification. COI partial sequences were used to construct the phylogenetic relationships among different species of genus Solenocera and to infer the origin of the studied Solenocera crassicornis. The applied molecular markers successfully identified the studied species to the species level. The genetic distances among S. crassicornis sequences from different countries revealed the Indo-West Pacific origin of S. crassicornis. The relationship between total length (TL) and total weight (TW) was TW = 0.035TL2.275 and r2 = 0.805 for males and TW = 0.007TL3.036 and r2 = 0.883 for females, indicating that females were heavier than males. Despite its social and economic relevance in the area, information on the hatching, larval rearing, and farming of S. crassicornis is scarce and requires future studies under Egyptian conditions.

scholarly journals BRIOZOOS CHEILOSTOMADOS DEL CARIBE COLOMBIANO

2016 ◽  
Vol 35 ◽  
Author(s):  
Paola Flórez Romero ◽  
Erika Montoya Cadavid ◽  
Javier Reyes Forero ◽  
Nadiezhda Santodomingo
Keyword(s):  
Continental Shelf ◽  
Marine Ecosystems ◽  
Soft Bottom ◽  
Marine Fauna ◽  
Geographic Ranges ◽  
The World ◽  
Growth Types ◽  
Soft Bottoms ◽  
Upper Slope

The Cheilostomes are the most diverse existent bryozoans group. Its species are commonly found in all the marine ecosystems around the world. In Colombia, however, information about them is scarce and limited to few localities. With the initiative of exploring the soft bottom biodiversity and completing the Colombian marine fauna inventories, INVEMAR-Macrofauna II exploration took place in March 2001, during which samples were collected on soft bottoms throughout the Colombian Caribbean from the continental shelf and the upper slope (20 – 500 m depth) by trawling. 62 species of Cheilostomes that belong to 39 families were found, 36 are first records for the Colombian Caribbean, 4 for the Great Caribbean and 1 for the Tropical West Atlantic. Bathymetric and geographic ranges are extended for 13 species. Taxonomical notes and images of the five species that are first records for the Greater Caribbean and the Tropical West Atlantic are included in this survey. It also includes remarks about the distribution, substrata, and growth types of Cheilostomata studied.

scholarly journals Soundscape of a management and exploitation area of benthic resources in central Chile

2017 ◽  
Vol 43 (5) ◽  
pp. 993-997
Author(s):  
Alfredo Borie ◽  
Natalia P.A. Bezerra ◽  
Sebastian A.L. Klarian ◽  
Paulo Travassos
Keyword(s):  
Habitat Type ◽  
Acoustic Method ◽  
Rocky Reef ◽  
Sea Waves ◽  
Central Chile ◽  
Distinct Frequency ◽  
Commercially Important ◽  
Night And Day ◽  
Passive Acoustic ◽  
Benthic Resources

Acoustic ecology is an emerging and poorly known field of research. Soundscape has been used to infer the behavior of several species in different environments and can serve as a reliable indicator of the habitat type and quality; also, it is believed that it is an important factor for larvae orientation in settlement areas. We used the passive acoustic method to evaluate the soundscape of a management and exploitation area of benthic resources, a rocky reef area in central Chile. It was possible to hear a continuous cracking sound during recording and underwater observations. We detected two distinct frequency bands with similar parameters during the night and day, a band between 90 and 300 Hz, which corresponded to the effects of sea waves (geophony), and a frequency band with a range of 1,500 to 2,700 Hz (biophony), with a fundamental frequency of 2,070 Hz. Both bands had similar energy (~88.0 dB re: 1V/µPa). These results show the relevant acoustic activity in the area, which may have important ecological implications for the recruitment of commercially important benthic resources.

The internal anatomy of Sandersiella chilenica Stuardo & Vega, 2011 (Crustacea: Cephalocarida)

2019 ◽  
Vol 40 (2) ◽  
pp. 176-180
Author(s):  
Claudio Valdovinos-Zarges
Keyword(s):  
Light Microscopy ◽  
Internal Anatomy ◽  
Reproductive Systems ◽  
Central Chile ◽  
Type Series ◽  
Histological Sections ◽  
Organ Systems ◽  
Soft Bottoms

Abstract The gross internal anatomy of the cephalocarid crustacean Sandersiella chilenicaStuardo & Vega, 2011 is described based on light microscopy of histological sections of three specimens of the type series, all collected in coastal soft bottoms off central Chile. Observations mainly concern the nervous, digestive, and reproductive systems, heart, haemocoel, and skeleto-musculature. The main organ systems and musculature are similar to those previously described for Hutchinsoniella macracanthaSanders, 1955, Lightiella magdaleninaCarcupino, Floris, Addis, Castelli & Curini-Galletti, 2006, and Sandersiella sp.

Ecological patterns in the benthic macrobiota across the continental shelf off central Chile

Ophelia ◽  
1995 ◽  
Vol 40 (3) ◽  
pp. 167-188 ◽  
Author(s):  
V A. Gallardo ◽  
F D. Carrasco ◽  
R. Roa ◽  
J. I. Cañete
Keyword(s):  
Continental Shelf ◽  
Central Chile ◽  
Ecological Patterns

Changes of macrobenthos composition under different ENSO cycle conditions on the continental shelf off central Chile

2007 ◽  
Vol 27 (7) ◽  
pp. 1002-1016 ◽  
Author(s):  
Javier Sellanes ◽  
Eduardo Quiroga ◽  
Carlos Neira ◽  
Dimitri Gutiérrez
Keyword(s):  
Continental Shelf ◽  
Enso Cycle ◽  
Central Chile

Size-structured patterns of piscivory of the longfin inshore squid (Loligo pealeii) in the mid-Atlantic continental shelf ecosystem

2006 ◽  
Vol 63 (4) ◽  
pp. 754-765 ◽  
Author(s):  
Mary E Hunsicker ◽  
Timothy E Essington
Keyword(s):  
Continental Shelf ◽  
Time Period ◽  
Size Constraints ◽  
Body Sizes ◽  
The Usa ◽  
Juvenile Stages ◽  
Commercially Important ◽  
Shelf Region ◽  
Loligo Pealeii

The longfin inshore squid (Loligo pealeii) dominates the landings in the USA mid-Atlantic continental shelf region, yet the potential ecological effects of harvesting this species are not known. Because squid feed on a wide variety of prey items, including juvenile stages of commercially important fish species, a full exploration on the predatory role of squid in this ecosystem is warranted. We examined the seasonal diet contents of L. pealeii and evaluated the importance of size constraints in governing patterns of piscivory. Our analyses showed that piscivory was dictated by size constraints, with larger squid demonstrating higher rates of piscivory than small squid. Squid were piscivorous at smaller sizes in the winter and spring than during the summer and autumn. Also, the frequency of piscivory was highest during the winter and spring, coincident with the time period when the number of vulnerable prey species was greatest. Our findings suggest that the frequency and intensity of piscivory are likely to be related to the duration of time that prey are vulnerable to predation, which in turn is dictated by the relative body sizes of L. pealeii and juvenile fishes.

Diets and trophic guilds of demersal fishes of the south-eastern Australian shelf

2001 ◽  
Vol 52 (4) ◽  
pp. 537 ◽  
Author(s):  
C. Bulman ◽  
F. Althaus ◽  
X. He ◽  
N. J. Bax ◽  
A. Williams
Keyword(s):  
Fish Species ◽  
Abundant Species ◽  
Trophic Guilds ◽  
The South ◽  
Important Species ◽  
Trawl Fishery ◽  
South Eastern ◽  
Total Fish ◽  
Wet Weight ◽  
Commercially Important

A total of 8200 stomach samples was collected from 102 fish species caught by trawl or gillnet during research surveys on the south-eastern Australian shelf from 1993 to 1996. Diet compositions were analysed based on percentages of wet weight of prey. Of the total fish examined, 70 species had sufficient stomach samples (i.e. >10) for further analysis. Ten trophic guilds were identified from cluster analysis. Benthic prey dominated the diets. However, analysis on a subset of 28 abundant species that were commercially and ecologically important, showed that pelagic prey was dominant, particularly for 12 quota species. This suggests that pelagic production contributes significantly to the trawl fishery production. Further analysis on the diets of these 28 species found that although fish was more important than invertebrate prey, there was no evidence of significant predation on commercially important species (quota species)by other fish species. A food web diagram was constructed, mostly based on the diet compositions, guild structure and relative abundance of commercially and ecologically important fish species, to show major trophic interactions of the shelf ecosystem.

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