scholarly journals Morphological convergence and adaptation in cave and pelagic scale worms (Polynoidae, Annelida)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Brett C. Gonzalez ◽  
Alejandro Martínez ◽  
Katrine Worsaae ◽  
Karen J. Osborn
Keyword(s):  
Shallow Water ◽  
Water Column ◽  
Phylogenetic Analyses ◽  
Generalized Least Squares ◽  
Lifestyle Modifications ◽  
Ground Pattern ◽  
Phylogenetic Reconstructions ◽  
Morphological Adaptations ◽  
Anchialine Caves ◽  
Shallow Water Species

AbstractAcross Annelida, accessing the water column drives morphological and lifestyle modifications—yet in the primarily “benthic” scale worms, the ecological significance of swimming has largely been ignored. We investigated genetic, morphological and behavioural adaptations associated with swimming across Polynoidae, using mitogenomics and comparative methods. Mitochondrial genomes from cave and pelagic polynoids were highly similar, with non-significant rearrangements only present in cave Gesiella. Gene orders of the new mitogenomes were highly similar to shallow water species, suggestive of an underlying polynoid ground pattern. Being the first phylogenetic analyses to include the holopelagic Drieschia, we recovered this species nested among shallow water terminals, suggesting a shallow water ancestry. Based on these results, our phylogenetic reconstructions showed that swimming evolved independently three times in Polynoidae, involving convergent adaptations in morphology and motility patterns across the deep sea (Branchipolynoe), midwater (Drieschia) and anchialine caves (Pelagomacellicephala and Gesiella). Phylogenetic generalized least-squares (PGLS) analyses showed that holopelagic and anchialine cave species exhibit hypertrophy of the dorsal cirri, yet, these morphological modifications are achieved along different evolutionary pathways, i.e., elongation of the cirrophore versus style. Together, these findings suggest that a water column lifestyle elicits similar morphological adaptations, favouring bodies designed for drifting and sensing.

scholarly journals Multiple origins of deep-sea Asellota (Crustacea: Isopoda) from shallow waters revealed by molecular data

2008 ◽  
Vol 276 (1658) ◽  
pp. 799-808 ◽  
Author(s):  
Michael J Raupach ◽  
Christoph Mayer ◽  
Marina Malyutina ◽  
Johann-Wolfgang Wägele
Keyword(s):  
Shallow Water ◽  
Deep Sea ◽  
Morphological Characters ◽  
Molecular Data ◽  
Multiple Origins ◽  
Morphological Adaptations ◽  
The Family ◽  
Shallow Water Species ◽  
Water Species ◽  
Variable Group

The Asellota are a highly variable group of Isopoda with many species in freshwater and marine shallow-water environments. However, in the deep sea, they show their most impressive radiation with a broad range of astonishing morphological adaptations and bizarre body forms. Nevertheless, the evolution and phylogeny of the deep-sea Asellota are poorly known because of difficulties in scoring morphological characters. In this study, the molecular phylogeny of the Asellota is evaluated for 15 marine shallow-water species and 101 deep-sea species, using complete 18S and partial 28S rDNA gene sequences. Our molecular data support the monophyly of most deep-sea families and give evidence for a multiple colonization of the deep sea by at least four major lineages of asellote isopods. According to our molecular data, one of these lineages indicates an impressive radiation in the deep sea. Furthermore, the present study rejects the monophyly of the family Janiridae, a group of plesiomorphic shallow-water Asellota, and several shallow-water and deep-sea genera ( Acanthaspidia , Ianthopsis , Haploniscus , Echinozone , Eurycope , Munnopsurus and Syneurycope ).

A new shallow water species of Artemisina Vosmaer, 1885 (Microcionidae, Demospongiae; Porifera) from Northeastern Brazil

Zootaxa ◽  
2016 ◽  
Vol 4184 (2) ◽  
pp. 386 ◽  
Author(s):  
THAYNÃ CAVALCANTI ◽  
GEORGE GARCIA SANTOS ◽  
EDUARDO HAJDU ◽  
ULISSES PINHEIRO
Keyword(s):  
Shallow Water ◽  
Northeastern Brazil ◽  
Shallow Water Species ◽  
Water Species

Relevance of an integrative approach for taxonomic revision in sponge taxa: case study of the shallow-water Atlanto-Mediterranean Hexadella species (Porifera:Ianthellidae:Verongida)

2012 ◽  
Vol 26 (3) ◽  
pp. 230 ◽  
Author(s):  
Julie Reveillaud ◽  
Céline Allewaert ◽  
Thierry Pérez ◽  
Jean Vacelet ◽  
Bernard Banaigs ◽  
...  
Keyword(s):  
Shallow Water ◽  
Phylogenetic Reconstruction ◽  
Taxonomic Revision ◽  
Integrative Approach ◽  
Cryptic Species Complex ◽  
Surface Network ◽  
Natural Toxicity ◽  
Shallow Water Species ◽  
Water Species

The identification of sponges that lack a mineral skeleton is always highly challenging, especially for Hexadella species, which are also fibreless. Recently, the yellow species Hexadella pruvoti Topsent was identified as a cryptic species complex while the pink coloured Hexadella racovitzai Topsent showed two highly divergent lineages. We performed a COI phylogenetic reconstruction using 27 new Mediterranean Hexadella samples in order to confirm the presence of divergent lineages within both shallow-water species. Specimens were described with an integrative approach combining morphological and cytological investigations, biochemical profiling and assessment of natural toxicity in order to identify diagnostic characters for each taxon. H. topsenti, sp. nov. is distinguished from H. racovitzai by its colour, its surface network shape, divergent secondary metabolite patterns and toxicity values. H. crypta, sp. nov. differs from H. pruvoti by a different encrusting growth form when alive, and by distinctively colouring the ethanol fixative solution. In addition, H. pruvoti and H. crypta show different types of cells with inclusions as well as distinct metabolic fingerprints. Natural toxicity values, however, do not permit the separation of H. pruvoti and H. crypta. Our work shows that only the use of a combination of complementary tools can provide relevant descriptions for some problematic taxa.

Tanaidacea (Crustacea: Peracarida) from Japan. IV. Shallow-water species from Akajima with notes on the recolonization potential of tanaids

Zootaxa ◽  
2008 ◽  
Vol 1678 (1) ◽  
pp. 1 ◽  
Author(s):  
KIM LARSEN ◽  
MICHITAKA SHIMOMURA
Keyword(s):  
Phylogenetic Analysis ◽  
Shallow Water ◽  
New Genus ◽  
Abundant Species ◽  
Two New Species ◽  
Sandy Habitat ◽  
Nansei Islands ◽  
Shallow Water Species ◽  
Water Species ◽  
Preliminary Phylogenetic Analysis

Two new species of tanaids were collected from colonization traps deployed in a shallow water, sandy habitat off Akajima, Nansei Islands. One new parapseudidaen, Parapseudes arenamans, and one new nototanaidaen genus and species, Paranesotanais longicephalus, are described herein. A preliminary phylogenetic analysis of the closest genera confirms the validity of the new genus and suggests a close affinity between the Leptocheliidae and Nototanaidae. Paranesotanais longicephalus was by far the most abundant species in the habitat. Parapseudes arenamans is faster in colonization of vacant substrate (opportunistic species), while being an inferior competitor to Paranesotanais longicephalus later in succession. A key to Nesotanais and Paranesotanais is provided.

scholarly journals Fossil and modern sponge fauna of southern Australia and adjacent regions compared: interpretation, evolutionary and biogeographic significance of the late Eocene ‘soft’ sponges

2016 ◽  
Vol 85 (1) ◽  
pp. 13-35 ◽  
Author(s):  
Magdalena Łukowiak
Keyword(s):  
New Zealand ◽  
Shallow Water ◽  
Environmental Context ◽  
Late Eocene ◽  
Shallow Marine ◽  
Marine Communities ◽  
Shallow Water Species ◽  
Water Species

The late Eocene ‘soft’ sponge fauna of southern Australia is reconstructed based on disassociated spicules and is used to interpret the paleoecology and environmental context of shallow marine communities in this region. The reconstructed sponge association was compared with coeval sponge assemblages from the Oamaru Diatomite, New Zealand, and with the modern ‘soft’ sponge fauna of southern coastal of Australia. Based on the predominance of shallow- and moderately shallow-water species, the late Eocene assemblage is interpreted to have inhabited waters depths of about 100 m. This contrast with the spicule assemblage from New Zealand, which characterized deeper waters based on the presence of numerous strictly deepwater sponge taxa, and the absence of spicules of shallow-water demosponges represented in the Australian material. The southern Australian Eocene sponge assemblages have clear Tethyan affinities evidenced by the occurrence of sponges known today from diverse regions. This distribution suggests much wider geographical ranges of some sponge taxa during the Eocene. Their present distributions may be relictual. The modern sponge fauna inhabiting southern Australian waters shows only moderate differences from these of the late Eocene. Differences are more pronounced at lower taxonomic levels (family and genus).

scholarly journals Genesis and Evolution of Ferromanganese Crusts from the Summit of Rio Grande Rise, Southwest Atlantic Ocean

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 349 ◽  
Author(s):  
Mariana Benites ◽  
James R. Hein ◽  
Kira Mizell ◽  
Terrence Blackburn ◽  
Luigi Jovane
Keyword(s):  
Atlantic Ocean ◽  
Shallow Water ◽  
Water Column ◽  
Rio Grande ◽  
Intermediate Water ◽  
Mode Water ◽  
Southwest Atlantic ◽  
Ferromanganese Crusts ◽  
Depositional Processes ◽  
Water Depths

The Rio Grande Rise (RGR) is a large elevation in the Atlantic Ocean and known to host potential mineral resources of ferromanganese crusts (Fe–Mn), but no investigation into their general characteristics have been made in detail. Here, we investigate the chemical and mineralogical composition, growth rates and ages of initiation, and phosphatization of relatively shallow-water (650–825 m) Fe–Mn crusts dredged from the summit of RGR by using computed tomography, X-ray diffraction, 87Sr/86Sr ratios, U–Th isotopes, and various analytical techniques to determine their chemical composition. Fe–Mn crusts from RGR have two distinct generations. The older one has an estimated age of initiation around 48–55 Ma and was extensively affected by post-depositional processes under suboxic conditions resulting in phosphatization during the Miocene (from 20 to 6.8 Ma). As a result, the older generation shows characteristics of diagenetic Fe–Mn deposits, such as low Fe/Mn ratios (mean 0.52), high Mn, Ni, and Li contents and the presence of a 10 Å phyllomanganate, combined with the highest P content among crusts (up to 7.7 wt %). The younger generation is typical of hydrogenetic crusts formed under oxic conditions, with a mean Fe/Mn ratio of 0.75 and mean Co content of 0.66 wt %, and has the highest mean contents of Bi, Nb, Ni, Te, Rh, Ru, and Pt among crusts formed elsewhere. The regeneration of nutrients from local biological productivity in the water column is the main source of metals to crusts, providing mainly metals that regenerate rapidly in the water column and are made available at relatively shallow water depths (Ni, As, V, and Cd), at the expense of metals of slower regeneration (Si and Cu). Additionally, important contributions of nutrients may derive from various water masses, especially the South Atlantic Mode Water and Antarctic Intermediate Water (AAIW). Bulk Fe–Mn crusts from the summit of RGR plateau are generally depleted in metals considered of greatest economic interest in crusts like Co, REE, Mo, Te, and Zr, but are the most enriched in the critical metals Ni and Li compared to other crusts. Further investigations are warranted on Fe–Mn crusts from deeper-water depths along the RGR plateau and surrounding areas, which would less likely be affected by phosphatization.

scholarly journals Airborne Hyperspectral Imaging for Submerged Archaeological Mapping in Shallow Water Environments

2019 ◽  
Vol 11 (19) ◽  
pp. 2237 ◽  
Author(s):  
Alexandre Guyot ◽  
Marc Lennon ◽  
Nicolas Thomas ◽  
Simon Gueguen ◽  
Tristan Petit ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Shallow Water ◽  
Water Column ◽  
Sea Level ◽  
Hyperspectral Imagery ◽  
Airborne Lidar ◽  
Radiative Transfer Model ◽  
Invasive Technique ◽  
Transfer Model ◽  
Water Bottom

Nearshore areas around the world contain a wide variety of archeological structures, including prehistoric remains submerged by sea level rise during the Holocene glacial retreat. While natural processes, such as erosion, rising sea level, and exceptional climatic events have always threatened the integrity of this submerged cultural heritage, the importance of protecting them is becoming increasingly critical with the expanding effects of global climate change and human activities. Aerial archaeology, as a non-invasive technique, contributes greatly to documentation of archaeological remains. In an underwater context, the difficulty of crossing the water column to reach the bottom and its potential archaeological information usually requires active remote-sensing technologies such as airborne LiDAR bathymetry or ship-borne acoustic soundings. More recently, airborne hyperspectral passive sensors have shown potential for accessing water-bottom information in shallow water environments. While hyperspectral imagery has been assessed in terrestrial continental archaeological contexts, this study brings new perspectives for documenting submerged archaeological structures using airborne hyperspectral remote sensing. Airborne hyperspectral data were recorded in the Visible Near Infra-Red (VNIR) spectral range (400–1000 nm) over the submerged megalithic site of Er Lannic (Morbihan, France). The method used to process these data included (i) visualization of submerged anomalous features using a minimum noise fraction transform, (ii) automatic detection of these features using Isolation Forest and the Reed–Xiaoli detector and (iii) morphological and spectral analysis of archaeological structures from water-depth and water-bottom reflectance derived from the inversion of a radiative transfer model of the water column. The results, compared to archaeological reference data collected from in-situ archaeological surveys, showed for the first time the potential of airborne hyperspectral imagery for archaeological mapping in complex shallow water environments.

Environmental versus genetic causes of morphologic variability in bryozoan colonies from the deep sea

Paleobiology ◽  
1976 ◽  
Vol 2 (2) ◽  
pp. 156-165 ◽  
Author(s):  
Thomas J. M. Schopf
Keyword(s):  
Shallow Water ◽  
Deep Sea ◽  
Fossil Record ◽  
Water Regime ◽  
Level Population ◽  
Total Variance ◽  
Genetic Causes ◽  
Single Genotype ◽  
Shallow Water Species ◽  
Water Species

Bryozoans are colonial animals and this permits the partitioning of their morphologic variability into components of within colony (i.e. within a single genotype) and between colony (i.e. between genotype) variance. These data have been obtained for four species of the endemic deep-sea genus Euginoma for a series of characters. In 8 comparisons, one component of the total variance dominated at the 5% level. Population (between colony) variance contributed significantly to the total variance in 63% of the comparisons (5 of 8); individual (within colony) variance contributed significantly to the total variance in 37% of the comparisons (3 of 8).Compared to shallow water species, the surprising feature of the deep-sea data is that the between colony component of variance is as high as it is. Possibly in the more stable, deep-sea environment, the genotypic contribution to the variance of each individual colony is expressed to a greater degree than in the more variable, shallow water regime. If so, then analyses of variability in colonial animals may be an independent means of ascertaining stability gradients in the fossil record.

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