Aglaophamus Kinberg, 1865
Aglaophamus sp. 2
Voucher. SEA LION: station 1MFC and station 8MFA.
Diagnosis. Small sized species; all vouchers incomplete, the largest voucher (SEA LION: station 8MFA) 3mm long and 0.8mm wide for 20 chaetiger long fragment. Prostomium subspherical, about as wide as long, with a V-shaped posterior margin, extending over the first chaetiger; a pair of nuchal organs near the posterior corners of prostomium; a pair of conical antennae in the anterior corners of the prostomium and a pair of palps inserted posteriorly on ventrum the prostomium. Proboscis not everted. Branchiae (inter-ramal cirri) involute; appearing abruptly (of similar size to those in subsequent chaetigers) from chaetiger 9; small; present until end of 20 chaetiger long fragment. Parapodia biramous; unadorned - no particularly enlarged lobes present, with the exception of superior lobe over notopodia, which is erect and enlarged (refer to the image for details). Dorsal cirri small, conical in chaetiger 1; from chaetiger 2 small, somewhat foliose, oval, distally abruptly produced into sharp, slender tip (refer to the image). Ventral cirri particularly well developed in chaetiger 1, where skittle-shaped (slender, but with wider base and thin distally); well developed in other chaetigers, tapering, cirriform. Preacicular chaetae stout, cross-barred in both rami. Postacicular chaetae in notopodia long, stouter spinulose and slender (appearing smooth) present; in neuropodia long, slender, appearing faintly cross-barred (articulation longer than in cross-barred pre-acicular chaetae). Pygidium not observed.
Remarks. Several Aglaophamus species with the late start of branchiae and relatively simple, unadorned parapodia similar to the FI specimens are known from the region. A. erectanoides Hartmann-Schröder, 1965 where branchiae appear from chaetigers 8-10, A. posterobranchus Hartman, 1967 where branchiae start between chaetigers 9-16 (mostly 12), A. groenlandiae Hartman, 1967 with branchiae from chaetiger 12, A. paramalmgreni Hartmann-Schröder and Rosenfeldt, 1992 with branchiae from chaetiger 12 and A. digitatus Hartman, 1967 with branchiae from chaetiger 7. Of these, A. posterobranchus, and A. digitatus also possess enlarged superior lobe above notopodia as does Falkland Is. specimen (this lobe is also present, but rudimentary in A. paramalmgreni and A. groenlandiae, while absent in A. erectanoides). Aglaophamus digitatus also shares foliose form of dorsal cirrus, which appears to be much smaller than in Falkland Island specimens, and protrudes well beyond any other lobe associated with notopodia. Further differences lie in the shape of prostomium, which is very narrow and elongated and in presence of small conical protuberance in notopodia. At present we cannot assign Falkland Island morphotypes unambiguously to any species know from the area, but further work will be necessary to establish if it represents a new species. Given its very small size we cannot exclude possibility that it is a juvenile.
