Molecular and carbon isotopic variability of hydrocarbon gases from mud volcanoes in the Gulf of Cadiz, NE Atlantic

Diapirs and mud volcanoes (MVs) are formed by the migration and extrusion of fluids and mud to the seafloor, respectively. In the Gulf of Cádiz there are ca. 60 MVs and several diapirs with different environmental conditions and seepage activity. Previous studies, mainly on MVs, have demonstrated that the invertebrate fauna associated with these seafloor structures can be very diverse, including chemosymbiotic species, mostly mollusks and frenulate polychaetes, as well as vulnerable suspension feeders, such as cold-water corals and sponges, among others. Previous studies of the bryozoan fauna in this area have recorded species belonging to 28 families. One of these families is Phidoloporidae, which comprises 27 genera worldwide, including the common Rhynchozoon, Reteporellina, and Reteporella. In the present study, two species belonging to Reteporella are redescribed, and a new species is described from diapirs and MVs on the shelf and slope of the Gulf of Cádiz. The samples were collected during several oceanographic expeditions carried out by the Instituto Español de Oceanografia. This genus is well represented in the NE Atlantic Ocean and the Mediterranean Sea, and our study extends its occurrence on MVs and diapirs fields of the Gulf of Cádiz.

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Deep-sea ophiuroids (Echinodermata: Ophiuroidea: Ophiurida) from the Gulf of Cadiz (NE Atlantic)

Zootaxa ◽

10.11646/zootaxa.2754.1.1 ◽

2011 ◽

Vol 2754 (1) ◽

pp. 1 ◽

Cited By ~ 13

Author(s):

CLARA F. RODRIGUES ◽

GORDON L. J. PATERSON ◽

ANDREW CABRINOVIC ◽

MARINA R. CUNHA

Keyword(s):

Deep Sea ◽

Cold Water ◽

Cold Seep ◽

Mud Volcanoes ◽

Gulf Of Cadiz ◽

Ne Atlantic ◽

Morphological Adaptations ◽

Gulf Of Cádiz ◽

High Species Richness ◽

Distinct Separation

The Ophiuroidea collected from mud volcanoes and adjacent bathyal environments from the Gulf of Cadiz are reviewed. Thirteen species from six families—Ophiacanthidae, Ophiactidae, Amphiuridae, Amphilepididae, Ophiuridae and Ophiolepididae—were identified. A direct relationship to the chemosynthetic assemblages has not been established as the ophiuroids found in the mud volcanoes do not appear to have novel morphological adaptations and also occur in non-reducing environments. The ophiuroid fauna from the Gulf of Cadiz differs from other cold seep regions not only by the high species richness but also because members of Amphiuridae are dominant both in number of species and abundance. One species previously unknown, Ophiopristis gadensis sp. nov., (Ophiacanthidae) was collected from a dead cold-water coral thicket at the flank of a mud volcano and differs from its congeners in the type of disk spines which are more rugose and not smooth as in most of the other species, the presence of the thickened integument in larger specimens and the distinct separation between the oral papillae and the second oral tentacle scales.

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Thyasiroidea (Mollusca: Bivalvia) from the mud volcanoes of the Gulf of Cadiz (NE Atlantic)

Zootaxa ◽

10.11646/zootaxa.1752.1.2 ◽

2008 ◽

Vol 1752 (1) ◽

pp. 41 ◽

Cited By ~ 24

Author(s):

CLARA F. RODRIGUES ◽

P. GRAHAM OLIVER ◽

MARINA R. CUNHA

Keyword(s):

Deep Water ◽

The Other ◽

Mud Volcanoes ◽

Gulf Of Cadiz ◽

Ne Atlantic ◽

Anatomical Features ◽

Gulf Of Cádiz

The Thyasiroidea collected from the mud volcanoes of the Gulf of Cadiz are reviewed. Of the seven species identified only one, Thyasira vulcolutre n. sp., is closely associated with a chemosynthetic setting. This species has anatomical features typical of chemosymbiotic taxa and is compared with T. sarsi (Philippi, 1845), T. southwardae Oliver & Holmes, 2006, T. oleophila Clarke, 1989 and T. methanophila Oliver & Sellanes, 2005. The other six, Thyasira (Parathyasira) granulosa (Monterosato, 1874), Thyasira tortuosa (Jeffreys, 1881), Thyasira obsoleta (Verrill & Bush, 1898), Axinulus croulinensis (Jeffreys, 1847), Mendicula ferruginosa (Forbes, 1844) and Leptaxinus minutus Verrill & Bush 1898, are previously known from typical deep-water benthic settings. Of these only A. croulinensis is known to harbour chemosymbionts although the gill anatomy of T. tortuosa suggests that it might also be chemosymbiotic. Thyasira vulcolutre is restricted to active seeps but there is no pattern in the distribution of the other species.

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Isotopic evidence (87Sr/86Sr, δ7Li) for alteration of the oceanic crust at deep-rooted mud volcanoes in the Gulf of Cadiz, NE Atlantic Ocean

Geochimica et Cosmochimica Acta ◽

10.1016/j.gca.2009.06.004 ◽

2009 ◽

Vol 73 (18) ◽

pp. 5444-5459 ◽

Cited By ~ 48

Author(s):

Florian Scholz ◽

Christian Hensen ◽

Anja Reitz ◽

Rolf L. Romer ◽

Volker Liebetrau ◽

...

Keyword(s):

Atlantic Ocean ◽

Oceanic Crust ◽

Mud Volcanoes ◽

Gulf Of Cadiz ◽

Ne Atlantic ◽

Isotopic Evidence ◽

Gulf Of Cádiz ◽

Ne Atlantic Ocean

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Leptostracans (Crustacea: Phyllocarida) from mud volcanoes at the Gulf of Cadiz (NE Atlantic) with description of a new species of Sarsinebalia Dahl, 1985

European Journal of Taxonomy ◽

10.5852/ejt.2021.736.1255 ◽

2021 ◽

Vol 736 ◽

pp. 102-136

Author(s):

Juan Moreira ◽

Patricia Esquete ◽

Marina R. Cunha

Keyword(s):

New Species ◽

Organic Substrates ◽

Mud Volcanoes ◽

Gulf Of Cadiz ◽

Ne Atlantic ◽

The Third ◽

Gulf Of Cádiz ◽

Mandibular Palp ◽

First Time ◽

A New Species

Three leptostracan species (Crustacea: Phyllocarida) are reported from mud volcanoes at the Moroccan margin of the Gulf of Cadiz (NE Atlantic). Nebalia strausi Risso, 1826 and N. abyssicola Fage, 1929 were found in experimentally deployed organic substrates in Mercator, Meknès and Darwin mud volcanoes; N. abyssicola was also found among bathymodiolin bivalves and is recorded for the first time in the Atlantic Ocean. The third species was collected from the Gemini mud volcanoes and is described herein as Sarsinebalia ledoyeri sp. nov. The new species is characterised by having the eyes provided with ommatidia and lacking pigment, the ventral margin of the eye is concave along distal half, the antennular scale is more than twice as long as wide, the second article of the mandibular palp bears one seta on lateral surface about 0.5 times as long as the article and one subterminal seta longer than the third article, the distal article of the maxilla II endopod is about 1.8 times as long as the proximal article, the maxilla II exopod is clearly longer than the endopod proximal article, the lateral margin of the pleopod I exopod lacks setae and the posterodorsal border of pleonites VI–VII is provided with rounded to pointed denticles.

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