Lysippe sp. 1

Ampharetinae Malmgren, 1866

Lysippe Malmgren, 1866

Lysippe sp. 1

Voucher. Sea Lion: station 45MFB

Diagnosis. Voucher is a complete specimen (branchiae missing), body relatively slender 14mm long and 1.2mm wide. Thorax consists of paleae bearing segment and 16 chaetigers, 13 of these uncinigers; abdomen with 12 uncinigers.  First three notopodia smaller than on subsequent segments, close together, second and third pair displaced dorsally. Abdominal segments without rudimental notopodia or neuropodial cirri, torus of first abdominal unciniger reduced. Pygidium formed of several small lobes.

Prostomium  Ampharete-type, trilobed  - the middle lobe almost square-shaped only slightly wider than lateral lobes, without glandular ridges. Lower lip crenulated with approximately 15 folds.  Paleae present, arising from cylindrical lobes, about 10 per fascicle, pale yellow in colour, very fine, small  (can be overlooked), slightly shorter than notochaetae, tapering into thin tip; under high magnification two types can be discerned, slightly thicker, narrowly limbate capillaries and simple threadlike capillaries.  

Four pairs of branchiae 2 + 2 arrangement, two groups separated by a distinct median gap; styles of branchiae missing,  branchiophores of equal size, connected laterally giving impression of raised ridge and obscuring prostomium dorsally.

Notochaetae few, long, smooth, limbate. Thoracic uncini with 4-5 small teeth above rostral tooth arranged in two alternating vertical rows; first two abdominal neuropodia of thoracic type; following abdominal neuropodia with different uncini, each with 5 teeth in lateral view, forming paw pattern in frontal view.

Remarks. Only two species in the genus Lysippe have been described with 17 thoracic chaetigers (including paleae), 13 thoracic uncinigers and cirriform branchiae (character which cannot be confirmed in FI specimen) - the type species L. labiata from Northern Europe (Spitzbergen) and L. nipponica from Nagasaki Bay, Japan in 50m. Both of these appear to differ from FI specimen in form of thoracic and/or abdominal uncini and it is likely that these represent a new species. However careful examination of type specimens will be necessary to confirm this. 

Classification: 
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith