Aurivillialepas calycula ( Aurivillius, 1898 )

Innocenti, Gianna, Geronimo, Raffaella Di & Newman, William A., 2015, A range extension of a deep-sea barnacle of the genus Aurivillialepas (Cirripedia, Scalpellomorpha), a Macaronesian and amphitropical refugial genus having Mesozoic affinities, Zootaxa 3974 (2), pp. 257-266 : 259-260

Aurivillialepas calycula ( Aurivillius, 1898)

Material examined. 2 specimens plus 2 complemental males, 42°49.188'N, 11°46.895'W, - 909 m, 3 August 2011, coll. Indemares 0 711 (J. Cartes, CSIC), one specimen on Madrepora oculata ( MZUF 602) ( Figs. 1–3 ); 2 specimens, St. 584 (38°31’N, 26°49’15”W), SE of Terceira, Azores, - 845 m, 16 July 1895 ( MOM 335116) ( Fig. 4 ).

Diagnosis. Capitulum with 14 plates, including subrostrum. RLs overlapping CLs beneath L. Plates thick, sculptured with longitudinal and checked ridges. C quite arched. S triangular with apico-basal ridge dividing the plate almost equally. T rhomboidal with a marked groove down near the middle. RLs scalene towards R, slightly curved inwards. R triangular slightly convex with a groove on either side of the median groove above SR.

Description. The specimens were not disarticulated nor dissected as they have been directly preserved in relatively pure ethanol and, therefore, their tissues are presently very stiff. Two complemental males were detached from between R and SR of one specimen in order to examine and photograph them ( Fig. 3 ).

Adult capitular length 18 mm and 20 mm for the small and large specimen, respectively. Capitular plates thick, covered with a thin, tan but largely transparent cuticle, major plates marked by longitudinal ridges crossed by horizontal growth lines (reticulate); RLs overlapping CLs.; C elongated, bending slightly inwards, arched, reticulated; S triangular, apical part slightly inclined towards tergum, apico-basal ridge dividing reticulated plate almost equally; T rhomboidal, reticulated on both sides of median grooved ridge: R triangular, higher than wide, slightly convex, outer surface with largest longitudinal ridge medial; almost equilaterally triangular but higher than wide, with inwardly bent apex strongly convex transversely, lateral margins concave; outer surface with longitudinal ridges; S equilaterally triangular, strongly convex transversely, curving towards carina; lateral and basal margins concave; R triangularly scalene, wider than high; slightly curved inwards, inclined towards rostral side, apex rounded; RL with carinal and rostrolateral margins concave, basal margin slightly concave; carinal margin longer than rostral margin, outer surface with marked transverse growth lines, longitudinal ridges and grooves, radially diverging from apex; L low, wide, slightly curved, forming scalene triangle, strong apico-basal ridge extending from apex near scutal margin, tergal margin short, about 0.5 times length of scutal margin, with three marked longitudinal ridges on surface of plate towards tergum, fine growth lines evident; CL triangular, wider than high, curved, with sub-median, apico-basal fold near median side, three marked ridges on each side of fold; fine growth lines evident, carinal margin shorter than median lateral margin.

Peduncle trapezoidal, 3–4 mm high, covered by ~26 tiers standing in imbricating whorls 8 or so plates high, plates covered by the same thin cuticle as the capitular plates, whorls decreasing in number downwards, plates triangular, apex obtuse ornamentation lacking ( Fig. 2 ).

Complemental males ( Fig. 3 ) attached to upper surface of SR; capitulum with the usual 6 plates, R-S-T-C, plus L and CLs and traces of RLs, major plates characterised by fine growth lines, S and T with traces of apico-basal ridges; T elongated on scutal margin, rounded on carinal margin. S triangular, R triangular and slightly bent inward, L rhomboidal, CL and traces of RL triangular, C strongly curved, apex bent inward. Peduncle short, naked.

Figures

FIGURE 1. Aurivillialepas calycula: from the left to right and from above to below: right lateral view of both specimens; left lateral view; carinal view; rostral view. White bar = 5.0 mm (MZUF 602).

FIGURE 2. Aurivillialepas calycula: right lateral view, SEM images of A, scutum; B, tergum and carina; C, peduncle and rostrolatus. White bar = 2.0 mm.

FIGURE 3. Aurivillialepas calycula: complemental male, left lateral and right lateral views respectively (MZUF 602), remarkable for a scillaelepadine male in having all capitular plates except SC (albeit RL appears to be missing on right side). White bar = 1.0 mm.

FIGURE 4. Aurivillialepas calycula: right lateral view, specimen from the Museum Oceanographique de Monaco (MOM 335116). White bar = 5.0 mm.