Aurospio abranchiata Neal, Paterson & Soto, 2016
- GBIF Backbone Taxonomy
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- Paterson, Gordon L. J.; Neal, Lenka; Altamira, Iris; Soto, Eulogio H.; Smith, Craig R.; Menot, Lenaick; Billett, David S. M.; Cunha, Marina R.; Marchais-Laguionie, Clare; Glover, Adrian G. New Prionospio and Aurospio Species from the Deep Sea (Annelida: Polychaeta). Zootaxa. 4092(1): 1-32 (2016).
- Aurospio abranchiata
Etymology. abranchiata — refers to the absence of branchiae. Ecology. A. abranchiata sp. nov. was the second most abundant spionid species found in the canyons of the Iberian margin by the HERMES programme. However, it achieved higher densities in mid-depth canyons (around 3400 m) than in deep-water canyons with highest densities found in Cascais canyon, where it replaced P. vallensis sp. nov. as the most dominant spionid species. Cascais canyon is considered to be the most quiescent of the three canyons studied along the Portuguese margin. Cascais canyon also had the lowest abundance, but highest diversity and evenness, of polychaete assemblages. Aurospio abranchiata sp. nov. was also found in Setúbal canyon at 3400 m during RRS Discovery cruise 186 in 1989, where it was highly dominant, contributing nearly 30 % of the total polychaete abundance. The increased density during D 186 compared with densities recorded during the HERMES program is difficult to interpret as different mesh-sized sieves were used. A. abranchiata sp. nov. is a very slender species and larger numbers could have been caught in the 0.3 - mm mesh used during D 186 than in 0.5 - mm and 1 - mm mesh used during the HERMES sampling program. The species is also quite numerous in the sediment samples from the Porcupine Abyssal Plain where it reaches abundances of 40 individuals per metre 2. FIGURE 14. Aurospio abranchiata sp. nov. Porcupine Abyssal Plain (Bengal 5 _ D 231 _ 13368 # 20 sp 81). a) Dorsal view of anterior chaetigers; scale bar = 100 µm. b) Mid-body chaetigers showing dorsal folds; scale bar = 100 µm. c) Detail of anterior chaetigers scale bar = 100 µm. The absence of branchiae provides an interesting insight into evolutionary adaptations in these deep-sea spionids. The deep-sea species of Aurospio — A. dibranchiata, A. foodbancsia, and A. abranchiata sp. nov. show a reduction both in the size of branchiae and also in the number. A. dibranchiata has two pairs of small branchiae, A. foodbancsia has one pair while A. abranchiata sp. nov. has no branchiae. The absence of branchiae in A. abranchiata sp. nov. could be compensated by extremely large notopodial lamellae, which are also a diagnostic feature of this species.
Material examined: 97 specimens examined in total. Holotype: Cascais canyon: RRS Charles Darwin, cruise 179, April – May 2006, St. 56823 # 2 2006.04. 27, 38 ° 18.01 ’ N, 09 ° 47.02 ’ W, 3218 m, megacore (NHMUK 2015: 1043). Paratypes: Portuguese margin: Nazaré canyon RSS Discovery 297 August 2005, St. 15755 # 1 39 º 30.62 ’ N, 09 º 56.19 ’ W, 3461 m, 3 individuals; St. 15760 # 1, 39 º 30.02 ’ N, 09 º 56.17 ’ W 3465 m, 5 individuals; St. 15762 # 1, 39 º 30.02 ’ N, 09 º 56.22 ’ W, 3464 m, 2 individuals; St. 15758 # 6, 39 º 34.99 ’ N, 10 º 19.00 ’ W, 4335 m, 5 individuals; St. 15765 # 2, 39 º 35.00 ’ N, 10 º 19.04 ’ W, 4336 m 4 individuals.
- Paterson, Gordon L. J.; Neal, Lenka; Altamira, Iris; Soto, Eulogio H.; Smith, Craig R.; Menot, Lenaick; Billett, David S. M.; Cunha, Marina R.; Marchais-Laguionie, Clare; Glover, Adrian G. (2016). New <em>Prionospio</em> and <em>Aurospio</em> Species from the Deep Sea (Annelida: Polychaeta). <em>Zootaxa.</em> 4092(1): 1-32.