The occurrence of pycnogonids associated with the volcanic structures of Bransfield Strait central basin (Antarctica)

• Published in: Scientia Marina
• Main Authors: Munilla, Tomás, Soler-Membrives, Anna
• Format: Article in Journal/Newspaper
• Language: English
• Published: Consejo Superior de Investigaciones Científicas 2007
• Subjects: Antarctic waters; Bransfield Strait; Gebrap-96 Cruise; Pycnogonida; volcanic structures; aguas antárticas; Estrecho de Bransfield; campaña Gebrap-96; estructuras volcánicas; Antarctic; Livingston Island; Draga; Estrecho; Roca; Estrecho Bransfield; Central Basin; Antarc*; Antarctica; Antártida
• Online Access: https://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/223; https://doi.org/10.3989/scimar.2007.71n4699

Fifty-four specimens of pycnogonids belonging to twenty-two species, eight genera and six families were collected with a rocky dredge during the cruise Gebrap-96 in the central basin of Bransfield Strait, from depths between 647 and 1592 m. The richest station in terms of abundance and biomass was DR6 (south of Livingston Island), which was also the shallowest one; at this relatively shallow depth food is more available than in deeper waters. The families Nymphonidae and Colossendeidae had the same number of specimens (21 specimens; 39% abundance each). The most abundant species were Nymphon villosum and N. proximum. Pallenopsis buphthalmus was collected for only the third time. The collections increased the geographical distribution of three species and the depth range of six species. The volcanic structures sampled were inactive during 1996, since none of the specimens showed signs of hydrothermal phenomena. This collection was typically representative of the west Antarctic benthic zone. En la expedición Gebrap-96 se capturaron 54 picnogónidos pertenecientes a 22 especies, 8 géneros y 6 familias. Se prospectaron fondos del Estrecho de Bransfield, entre 647 y 1592 m con una draga de roca. La estación con más riqueza biológica fue la DR6 (sur de Livingston), la menos profunda de entre las prospectadas; a dicha profundidad hay más disponibilidad alimentícia que en aguas inferiores. Las familias más abundantes (Colossendeidae y Nymphonidae) tienen el mismo número de individuos (21; 39% abundancia cada una). Las especies más abundantes fueron Nymphon proximum y N. villosum, siendo Pallenopsis buphthalmus tercera cita mundial. Tres especies aumentan su distribución geográfica y seis su batimetría. El análisis de la picnogonifauna permite afirmar que las formaciones volcánicas permanecían inactivas en el año del muestreo, siendo esta fauna la típica de la Antártida occidental.