New data on the life history and ecology of the deep-sea hooked squid Taningia danae

Sarsia ◽  
2003 ◽  
Vol 88 (4) ◽  
pp. 297-301 ◽  
Author(s):  
Guerra A. ◽  
Rocha F. ◽  
A. F. González
Keyword(s):  
Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 522
Author(s):  
Régis Santos ◽  
Wendell Medeiros-Leal ◽  
Osman Crespo ◽  
Ana Novoa-Pabon ◽  
Mário Pinho

With the commercial fishery expansion to deeper waters, some vulnerable deep-sea species have been increasingly captured. To reduce the fishing impacts on these species, exploitation and management must be based on detailed and precise information about their biology. The common mora Mora moro has become the main deep-sea species caught by longliners in the Northeast Atlantic at depths between 600 and 1200 m. In the Azores, landings have more than doubled from the early 2000s to recent years. Despite its growing importance, its life history and population structure are poorly understood, and the current stock status has not been assessed. To better determine its distribution, biology, and long-term changes in abundance and size composition, this study analyzed a fishery-dependent and survey time series from the Azores. M. moro was found on mud and rock bottoms at depths below 300 m. A larger–deeper trend was observed, and females were larger and more abundant than males. The reproductive season took place from August to February. Abundance indices and mean sizes in the catch were marked by changes in fishing fleet operational behavior. M. moro is considered vulnerable to overfishing because it exhibits a long life span, a large size, slow growth, and a low natural mortality.


2017 ◽  
Vol 4 (9) ◽  
pp. 170862 ◽  
Author(s):  
H. Ritchie ◽  
A. J. Jamieson ◽  
S. B. Piertney

Genome size varies considerably across taxa, and extensive research effort has gone into understanding whether variation can be explained by differences in key ecological and life-history traits among species. The extreme environmental conditions that characterize the deep sea have been hypothesized to promote large genome sizes in eukaryotes. Here we test this supposition by examining genome sizes among 13 species of deep-sea amphipods from the Mariana, Kermadec and New Hebrides trenches. Genome sizes were estimated using flow cytometry and found to vary nine-fold, ranging from 4.06 pg (4.04 Gb) in Paralicella caperesca to 34.79 pg (34.02 Gb) in Alicella gigantea . Phylogenetic independent contrast analysis identified a relationship between genome size and maximum body size, though this was largely driven by those species that display size gigantism. There was a distinct shift in the genome size trait diversification rate in the supergiant amphipod A. gigantea relative to the rest of the group. The variation in genome size observed is striking and argues against genome size being driven by a common evolutionary history, ecological niche and life-history strategy in deep-sea amphipods.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Randal A. Singer ◽  
Jon A. Moore ◽  
Edward L. Stanley

Abstract The deep ocean is frequently assumed to be a homogeneous system lacking the same diverse life history strategies found in shallower waters. However, as our methods for exploring the deep ocean improve, common assumptions about dispersal, reproduction and behavior are constantly being challenged. Fishes exhibit the most diverse reproductive strategies among vertebrates. Understanding life history strategies in deep-sea environments is lacking for many species of fishes. Here, we report a novel reproductive strategy where a fish (Parazen pacificus) provides parental care via mouth brooding. This behavior is observed from a specimen collected with eggs present in the buccal cavity, along with other specimens exhibiting pre-brooding morphologies. This is the first description of this unique life history trait in a deep-sea fish and fills in a gap in the larval literature for this family of fishes and prompts further investigation into other novel reproductive modes of deep-sea fauna.


Author(s):  
Henry Tiemann ◽  
Ilka Sötje ◽  
Blair D. Johnston ◽  
Per R. Flood ◽  
Ulf Båmstedt

The distribution pattern and nocturnal surface behaviour of the deep-sea medusa Periphylla periphylla in a Norwegian fjord was studied. Medusa abundance, size distribution and condition were determined, using surface collections, net tows and ROV-based video profiles. Only larger, mature medusae reached the surface and aggregated into small groups of both sexes, whereas juvenile medusae remained in deeper waters. Observations on the behaviour and cytology of aggregated medusae suggested a mating strategy. We hypothesize that this behaviour is the by-product of a holopelagic life history, developed in a more oceanic deep environment with low species abundance, as surface aggregation increases the chance of encounter and mating.


1998 ◽  
Vol 4 ◽  
pp. 7-36 ◽  
Author(s):  
Howard J. Spero

Application of planktonic foraminifera to micropaleontological, paleoceanographic and paleoclimatic research has enjoyed more than 150 years of activity. During the first century, foraminifera were used primarily for biostratigraphic analysis. Although fossil shells were recognized from beach sands and deep sea sediments as early as 1826 (d'Orbigny, 1826; Parker and Jones, 1865), it wasn't until Owen (1867) and the scientific results of the Challenger expedition (Brady, 1884) that the planktonic life habitat of these marine protozoans was clearly established. By the early 20th century, researchers were studying the biology of planktonic foraminifera at the cellular level (Rhumbler, 1901; Le Calvez, 1936), and linking their distributional patterns to regions of the ocean surface (Lohmann, 1920; Schott, 1935).


2002 ◽  
Vol 58 (2) ◽  
pp. 231-239 ◽  
Author(s):  
L.J López Abellán ◽  
E Balguerı́as ◽  
V Fernández-Vergaz

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