Contribution to the description of Fibulia myxillioides (Burton, 1932) and new records of the species at Burdwood Bank, after 90 years of its unique collection date

CRISTOBO J.; RÍOS P.; LAURA SCHEJTER

Galway

Conferencia; 10th. World Sponge Conference; 2017

Fibulia myxillioides (Burton, 1932) was described as Plumocolumella myxilliodes based on the specimens collected in the Malvinas (Falkland) Islands region onboard RRS ?William Scoresby? in 1927 and 1928. The species was recorded in 9 sites in the mentioned area, and its distribution comprises Malvinas Is. and Burdwood Bank (SW Atlantic Ocean). However, besides these records, no information regarding this species was published since then, with the exception of the genus transfer, first to Xytopsaga by De Laubenfels (1936), based on the type specimen and other specimens collected during the same expedition, and lately to Fibulia by van Soest (2007). Burton´s original description consisted in a synthetic paragraph and a draw of two complete specimens, with only few measures (and no ilustrations) of the spicules. In this contribution, we add 5 recent records of the species in Burdwood Bank about 90 years after its original (and unique) collection and record date, from samples collected during research cruises developed during 2013 and 2016, both onboard the RV ?Puerto Deseado?. We update the bathymetric range of the species from 81-267m (in Burton, 1932) to 608 m. We also describe and provide images of the yellow-brownish coloration in the living specimens and we present, for the first time, SEM images of all the spicules, with the recorded range of measures for Burdwood Bank. Based on the evidence and a bibliographic review, this is an endemic species from Malvinas/ Burdwood Bank region, and the oceanographic conditions (Malvinas Current) are probably related with the distribution pattern.