scholarly journals Mesophotic Gorgonian Corals Evolved Multiple Times and Faster Than Deep and Shallow Lineages

Diversity ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 650
Author(s):  
Juan A. Sánchez ◽  
Fanny L. González-Zapata ◽  
Carlos Prada ◽  
Luisa F. Dueñas

Mesophotic Coral Ecosystems (MCEs) develop on a unique environment, where abrupt environmental changes take place. Using a time-calibrated molecular phylogeny (mtDNA: mtMutS), we examined the lineage membership of mesophotic gorgonian corals (Octocorallia: Cnidaria) in comparison to shallow and deep-sea lineages of the wider Caribbean-Gulf of Mexico and the Tropical Eastern Pacific. Our results show mesophotic gorgonians originating multiple times from old deep-sea octocoral lineages, whereas shallow-water species comprise younger lineages. The mesophotic gorgonian fauna in the studied areas is related to their zooxanthellate shallow-water counterparts in only two clades (Gorgoniidae and Plexauridae), where the bathymetrical gradient could serve as a driver of diversification. Interestingly, mesophotic clades have diversified faster than either shallow or deep clades. One of this groups with fast diversification is the family Ellisellidae, a major component of the mesophotic gorgonian coral assemblage worldwide.

2020 ◽  
Author(s):  
Juan A. Sánchez ◽  
Fanny L. González-Zapata ◽  
Carlos Prada ◽  
Luisa F. Dueñas

1.SummaryMesophotic Coral Ecosystems (MCEs) promise hope for the shallow-water biota enduring rising temperatures and multiple environmental stressors. Using a time-calibrated molecular phylogeny (mtDNA: mtMutS), we examined the lineage membership of mesophotic gorgonian corals (Octocorallia: Cnidaria) in comparison to shallow and deep-sea lineages of the wider Caribbean-Gulf of Mexico and the Tropical Eastern Pacific. Our results show mesophotic gorgonians originating multiple times from old deep-sea octocoral lineages, whereas shallow-water species comprise younger lineages. The mesophotic gorgonian fauna in the studied areas are related to their zooxanthellate shallow-water counterparts in only two clades (Gorgoniidae and Plexauridae), where the shallow-deep gradient could serve as a driver of diversification. Interestingly, mesophotic clades have diversified faster than either shallow or deep clades. One of this groups with fast diversification is the family Ellisellidae, a major component of the mesophotic gorgonian coral assemblage worldwide.


2008 ◽  
Vol 276 (1658) ◽  
pp. 799-808 ◽  
Author(s):  
Michael J Raupach ◽  
Christoph Mayer ◽  
Marina Malyutina ◽  
Johann-Wolfgang Wägele

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 ).


Paleobiology ◽  
1976 ◽  
Vol 2 (2) ◽  
pp. 156-165 ◽  
Author(s):  
Thomas J. M. Schopf

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.


Author(s):  
P. A. Tyler ◽  
S. L. Pain ◽  
J. D. Gage

INTRODUCTIONThe reproductive biology of asteroids from a wide variety of ecological niches has been examined (Farmanfarmaian et al. 1958; Cognetti & Delavault, i962;Pearse, 1965; Chia, 1968; Crump, 1971; Jangoux & Vloebergh, 1973; Worley, Franz & Hendler, 1977; Barker, 1979; Shick, Taylor & Lamb, 1981). Most of the species within this class appear to show some degree of seasonal reproductive synchrony with very few species showing aseasonal reproduction (Shick et al. 1981). Although the seasonally reproducing asteroids show a wide variety of reproductive strategies, from planktotrophic larvae to direct development, they all occur in relatively shallow water and are thus subject to the seasonal fluctuations of the physico-chemical environment. Only two shallow-water species, Ctenodiscus crispatus (Shick et al. 1981) and Patiriella exigua (Lawson-Kerr & Anderson, 1978), have aseasonal reproduction in both males and females. However, the deep sea is the only major environment in the world's ocean for which we have no data for the reproductive cycle of asteroids.


2021 ◽  
Vol 168 (3-4) ◽  
Author(s):  
Marianna V. P. Simões ◽  
Hanieh Saeedi ◽  
Marlon E. Cobos ◽  
Angelika Brandt

Abstract Empirical and theoretical studies suggest that marine species respond to ocean warming by shifting ranges poleward and/or into deeper depths. However, future distributional patterns of deep-sea organisms, which comprise the largest ecosystem of Earth, remain poorly known. We explore potential horizontal range shifts of benthic shallow-water and deep-sea Crustacea due to climatic changes within the remainder of the century, and discuss the results in light of species-specific traits related to invasiveness. Using a maximum entropy approach, we estimated the direction and magnitude of distributional shifts for 94 species belonging to 12 orders of benthic marine crustaceans, projected to the years 2050 and 2100. Distance, direction, and species richness shifts between climate zones were estimated conservatively, by considering only areas suitable, non-extrapolative, and adjacent to the currently known distributions. Our hypothesis is that species will present poleward range-shifts, based on results of previous studies. Results reveal idiosyncratic and species-specific responses, with prevailing poleward shifts and a decline of species richness at mid-latitudes, while more frequent shifts between temperate to polar regions were recovered. Shallow-water species are expected to shift longer distances than deep-sea species. Net gain of suitability is slightly higher than the net loss for shallow-water species, while for deep-sea species, the net loss is higher than the gain in all scenarios. Our estimates can be viewed as a set of hypotheses for future analytical and empirical studies, and will be useful in planning and executing strategic interventions and developing conservation strategies.


Acarina ◽  
2021 ◽  
Vol 29 (2) ◽  
pp. 189-232
Author(s):  
Ilse Bartsch

Presently, 39 Lohmannella species are accepted as valid, but future examinations may prove some of them to be junior synonyms of others. This article lists the most important descriptive papers, as well as the former names for each of the 39 species. The characters of another five species, known by their adults, are outlined but not given a name. Based on the published data, short diagnoses as well as notes on the distribution and habitats are added. In addition, the poorly known female of Lohmannella bihamata is described and illustrated. This article provides a table of morphological characters that are meant to facilitate the identification of Lohmannella species. The genus Lohmannella is spread worldwide, inhabiting all water depths and all climatic zones; its representatives live in marine and fresh water. Although the majority of Lohmannella species have been found at sea, five species have been recovered from fresh or slightly brackish water. In the following sentences, the number of unnamed species is given in square brackets. Records of 33 [plus two] marine species are exclusively from the littoral and/or bathyal zone (0–1,000 m deep); records of three [plus three] species are from the deep sea (deeper than 1,000 m); and one record is from the littoral / deep sea depth range. Most species have been found in the temperate and polar areas: namely, 12 [plus two] have been recorded north of 23°N and 20 south of 23°S. The data from the tropics include a single shallow water (0–200 m deep) record, one unnamed species from the 400–520 m depth and one [plus two] species from the depth of more than 1,000 m. Most southern hemisphere shallow water species are morphologically distinct from the bathyal and abyssal species, as well as from the northern hemisphere species.


Polar Biology ◽  
2015 ◽  
Vol 39 (3) ◽  
pp. 461-471 ◽  
Author(s):  
Xikun Song ◽  
Cinzia Gravili ◽  
Jianjun Wang ◽  
Yacheng Deng ◽  
Yongqiang Wang ◽  
...  

Zootaxa ◽  
2016 ◽  
Vol 4184 (2) ◽  
pp. 386 ◽  
Author(s):  
THAYNÃ CAVALCANTI ◽  
GEORGE GARCIA SANTOS ◽  
EDUARDO HAJDU ◽  
ULISSES PINHEIRO

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