Altiverruca Pilsbry, 1916

Young, Paulo S., 2002, Revision of the Verrucidae (Crustacea, Cirripedia) from the Atlantic Ocean studied by Abel Gruvel (Travailleur and Talisman scientific expeditions), Zoosystema 24 (4), pp. 771-797 : 773-780

Genus Altiverruca Pilsbry, 1916

Altiverruca erecta ( Gruvel, 1900) ( Figs 1-4 )

Verruca erecta Gruvel, 1900: 243 ; 1902: 93, pl. 5, figs 7, 8; 1905: 172, figs 188, 189. — Hoek 1907: 9. — Nilsson-Cantell 1955: 219. — Zevina 1976: 1155.

Verruca erecta , sec. D – Altiverruca – Pilsbry 1916: 40. Altiverruca erecta – Zevina 1988: 39. — Buckeridge 1994: 93. — Young 1998a: 77; 1998c: 111, figs 3, 4; 2001: 744, fig. 27; 2002: 6.

TYPE MATERIAL. — Holotype by monotypy: Expédition du Talisman , S of Azores, stn 118, 34°46’N, 36°11’W, 3175 m, 1883, 1 spec. rc 2.5 mm ( MNHN Ci 62).

DIAGNOSIS. — Shell with growth lines prominent, without longitudinal ridges. Rostrum-carina suture nearly straight. Rostrum nearly rectangular, with a low articular ridge that separates upper crested surface directed toward base of scutum from the main parietal plate. Carina higher than rostrum. Tergum only with axial ridge prominent. Scutum with three articular ridges, apex strongly curved toward tergum. Mandible with three teeth, second and third tooth strongly cuspidate. Cirrus I with unequal rami, anterior ramus slightly smaller than posterior. Cirrus II with anterior ramus about 0.5 length of posterior. Intermediate articles of cirrus VI with three pairs of setae on anterior margin. Caudal appendage slightly shorter than protopodite.

DESCRIPTION

Shell ( Fig. 1 ) white, opercular valves nearly perpendicular to base of wall, with growth lines prominent on all plates; shell plates without longitudinal ridges; basal margin not thickened. Cuticle not persistent on wall and opercular valves. Rostrum-carina suture nearly straight except for the upper part, which is rounded to receive the rostrum ridge. Rostrum ( Fig. 1A, C ) nearly rectangular, a low articular ridge separates the upper crested surface directed toward base of scutum from the main smooth parietal portion of plate; rostrum and fixed scutum articulation without radius-like projection, apex not projected, straight. Carina ( Fig. 1A, B ) elongated, higher than rostrum, without radius-like projection toward fixed tergum; apex slightly projected, straight, one small ridge directed toward tergal axial ridge above single articular ridge. Fixed tergum ( Fig. 1B ) higher than fixed scutum, both

Young P. S.

sides with well-developed alar-like projections; apex curved toward fixed scutum. Fixed scutum ( Fig. 1B ) with alar-like process directed toward rostrum not differentiated and a wide radii-like process directed toward fixed tergum, apex slightly curved toward fixed tergum; internally, without adductor pit or ridge.

Tergum ( Fig. 1A ) quadrangular, with only axial ridge prominent and a slightly thickened occludent margin, with a wide and shallow depression below occludent margin; carinal area smooth. Scutum ( Fig. 1A ) smaller than tergum; with three articular ridges; axial ridge conspicuous, but well-marked at tergal border, and curving continuously toward rostral surface; second ridge thin and little developed; third ridge as a flat surface at apical portion; rostral area smooth, apex strongly curved toward tergum.

Labrum ( Fig. 2A ) with a series of about 41 simple teeth. Palp ( Fig. 2A ) short, thin, with few simple setae on inner margin and distal region. Mandible ( Fig. 2B ) with three teeth, distance between first and second twice the distance between second and third, second and third tooth strongly cuspidated; lower angle strongly denticulate. Maxilla I ( Fig. 2C ) with lower part projected; two large followed by two small spines at upper border, and four median and five smaller spines on lower projected border. Maxilla II ( Fig. 2D ) triangular, anterior margin with conspicuous concavity medially; covered by long simple setae, except in the concavity.

Cirrus I ( Fig. 3A ) with unequal rami, anterior ramus slightly shorter than posterior, covered with several long simple setae. Cirrus II ( Fig. 3B ) with anterior ramus about 0.5 length of posterior, articles little more protuberant; both rami covered by numerous long, simple and finely pinnate setae. Rami of cirri III-VI equal in length. Setal-article ratio about 7:1. Intermediate articles of cirrus VI ( Fig. 3C ) with width 0.4 length; three pairs of setae on anterior margin and a thin small setula between larger pair, longer setae finely pinnate; one long and

Revision of Verrucidae ( Crustacea, Cirripedia) studied by Gruvel

one small simple setae on posterior angle. Caudal appendage ( Fig. 3D ) with six articles, slightly shorter than protopodite; long simple setae on antero-distal margins of articles. Penis ( Fig. 3D ) long, 1.5 of protopodite, with few thin setulae at point. Number of articles of cirri I-VI and caudal appendage is presented in Table 1.

REMARKS

Altiverruca erecta was based on a single specimen from the Azores region ( Gruvel 1900, 1902) and subsequently recorded again from the Azores and the Mid-Atlantic Ridge ( Young 1998c, 2001) ( Fig. 4 ).

The sample examined from the Mid-Atlantic Ridge ( Young 1998c) varies somewhat with the type species: the rostrum-carinal suture is a little more undulated, cirrus I has rami of equal length and the median article of cirrus VI has only two pairs of setae on the anterior margin. The range from a straight to an undulation of the rostrumcarinal suture was also observed in the material studied by Young (2001). But the presence of only two pairs of setae on the anterior margin of cirrus VI may indicate it is another species. There is variation in the number of pairs of setae along the length of a ramus, but usually the median ones attain the maximum number for their species. The specimens examined by Young (2001) were taller than the type specimen and have their carina more elongated.

Altiverruca erecta , together with the next species, A. longicarinata , are included in Altiverruca s.s. as reviewed by Young (2002), which encompasses those verrucids with a delicate erect shell, the opercular plates perpendicular to the basis and no developed articular ridges between the rostrum and carina. They are usually deep-sea species, commonly being found deeper than 2000 m. A. erecta was dredged between 890-925 and 3375-3947 m.

Altiverruca longicarinata ( Gruvel, 1900) ( Figs 4-7 )

Verruca longicarinata Gruvel, 1900: 242 ; 1902: 91, pl. 5, figs 3, 4; 1905: 172, fig. 190. — Hoek 1907: 9. — Nilsson-Cantell 1955: 219. — Zevina 1976: 1155.

Verruca longicarinata , sec.D – Altiverruca – Pilsbry 1916: 40.

Verruca (Altiverruca) longicarinata – Zevina 1987: 1305, fig. 1.

Altiverruca longicarinata – Zevina 1988: 39. — Buckeridge 1994: 93. — Young 1995: 244; 1998a: 77; 1998c: 113; 2002: 6.

TYPE MATERIAL. — Lectotype by present designation: Expédition du Talisman, Sargasso Sea , drag. 117, 3432 m, 1883, rc 2.7 mm ( MNHN Ci 73); paralectotypes: same locality, 2 spec., rc 2.5 and 1.4 mm ( MNHN Ci 73).

DIAGNOSIS. — Shell with growth lines not prominent, without longitudinal ridges. Rostrum-carina suture difficult to discern. Rostrum nearly rectangular, with a straight rostro-carinal articulation; a low articular ridge separates upper flat surface directed toward base of scutum from the main parietal plate. Carina higher than rostrum. Tergum with three articular ridges, intermediate ridge wider than axial ridge. Scutum with two articular ridges. Cirrus I with unequal rami, anterior ramus slightly smaller than posterior. Cirrus II with anterior ramus about 0.5 length of posterior. Intermediate articles of cirrus VI with two pairs of setae on anterior margin. Caudal appendage with same length as protopodite.

Revision of Verrucidae ( Crustacea, Cirripedia) studied by Gruvel

DESCRIPTION

Shell ( Fig. 5 A-C) white, opercular valves nearly perpendicular to base of wall, with growth lines not prominent on all plates; shell plates without longitudinal ridges; basal margin not thickened. Cuticle not persistent on wall and opercular valves. Rostrum-carina suture difficult to discern, very similar to growth lines. Rostrum ( Fig. 5A, C ) nearly rectangular, with a straight rostro-carinal articulation, except for the tooth

Young P. S.

on upper part, a low articular ridge separates the upper flat surface directed toward base of scutum from the main parietal plate; rostrum and fixed scutum articulation without radius-like projection, apex projected, incurved. Carina ( Fig. 5A ) elongated, higher than rostrum, without radiuslike projection toward fixed tergum; apex broken (in original description it is strongly retroverted [ Gruvel 1900]). Fixed tergum ( Fig. 5B ) higher than fixed scutum, both sides with welldeveloped alar-like projections; apex slightly curved toward fixed scutum. Fixed scutum ( Fig. 5B ) with wide alar-like process directed toward rostrum and a wide radii-like process directed toward fixed tergum, apex curved toward fixed tergum; internally, without adductor pit or ridge.

Tergum ( Fig. 5A, D ) quadrangular, with three articular ridges; axial ridge prominent, intermediate ridge wider than axial ridge; upper ridge thin and marginal to occludent margin, with a conspicuous depression between upper and intermediate ridges; carinal area smooth. Internally smooth and flat; scutal margin nearly straight. Scutum ( Fig. 5A, E ) smaller than tergum; with two articular ridges; axial ridge conspicuous, thin; second ridge as wide as axial ridge; rostral area smooth, apex slightly curved toward tergum, thickened. Internally with a concavity for adductor muscle conspicuous on upper portion; tergal margin nearly straight, a small tooth projecting at lower portion.

Labrum ( Fig. 6A ) with a series of about 35 simple teeth. Palp ( Fig. 6A ) short, thin, with

Revision of Verrucidae ( Crustacea, Cirripedia) studied by Gruvel

few simple setae on outer margin and distal region. Mandible ( Fig. 6B ) with three teeth, distance between first and second twice distance between second and third, second and third tooth with subsidiary cusps; lower angle strongly denticulate. Maxilla I ( Fig. 6C ) with lower part strongly projected; two large followed by four smaller spines at upper border and four intermediate spines on lower projected border. Maxilla II ( Fig. 6D ) triangular, anteri- or margin with conspicuous concavity medially; covered by long simple setae, except on the concavity.

Cirrus I ( Fig. 7A ) with unequal rami, anterior ramus slightly shorter than posterior, covered with several long simple setae. Cirrus II ( Fig. 7B ) with anterior ramus about 0.5 length of posterior, articles little more protuberant than those from cirri III; both rami covered by numerous long, simple and finely pinnate setae. Rami of cirri III-VI equal in length. Setal-article ratio about 5:1. Intermediate articles of cirrus VI ( Fig. 7C ) with width 0.6 length; two pairs of setae on anterior margin and a thin small setula between large pair, longer setae finely pinnate; two or three fine simple setae on posterior angle. Caudal appendage ( Fig. 7D ) with eight articles, same length as protopodite; long simple setae on antero-distal margins of articles. Penis ( Fig. 7E ) short, same length as protopodite, with few thin setulae at point. Number of articles of cirri I-VI and caudal appendage is presented in Table 2.

REMARKS

The remarkable projected apex of the carina cited by Gruvel (1900), in which the main one characterizes this species, was broken in all the type specimens examined except for the smallest one. Although this long apex probably can be broken even in nature, this character is a diagnostic one. The low growth lines with the undistinguishable rostro-carinal suture, the straight suture and the upper surface of the rostrum directed toward the scutum are better characters for distinguishing this species. Foster & Buckeridge (1995b: 367) considered V. longicarinata to be synonymous with V. quadrangularis Hoek, 1883 , but I consider the above described characters to be sufficient to distinguish the species.

The two paralectotypes are smaller than the lectotype (rc 2.5 and 1.4 mm). The larger paralectotype has the articular ridge of the rostrum more conspicuous than the lectotype and, the smaller specimen has the tergum with only the axial ridge conspicuous; the apex of carina is projected but not so long as that figured by Gruvel (1902: pl. 5, figs 3, 4).

Altiverruca longicarinata has a wide distribution in the North Atlantic occurring from the Guayama Basin and Sargasso Sea to the Mid- Atlantic Ridge between depths of 2490 and 3432 m ( Fig. 4 ).

Figures

FIG. 1. — Altiverruca erecta (Gruvel, 1900), lectotype; A, rostrocarinal view; B, fixed-tergum and fixed-scutum views; C, rostrum-fixed-scutum view. Scale bar: 1 mm.

FIG. 2. — Altiverruca erecta (Gruvel, 1900), lectotype; A, labrum and palp; B, mandible; C, maxilla I; D, maxilla II. Scale bar: 0.1 mm.

FIG. 3. — Altiverruca erecta (Gruvel, 1900), lectotype; A, cirrus I; B, cirrus II; C, median article of cirrus VI; D, protopodite of cirrus VI, penis and caudal appendage. Scale bars: 0.2 mm.

FIG. 4. — Geographic distribution of Altiverruca erecta (Gruvel, 1900) (-) and A. longicarinata (Gruvel, 1900) (Δ).

FIG. 5. — Altiverruca longicarinata (Gruvel,1900), lectotype; A, rostro-carinal view; B, fixed-tergum and fixed-scutum view; C, rostrum- fixed-scutum view; D, tergum, internal view; E, scutum, internal view. Scale bars: 1 mm.

FIG. 6. — Altiverruca longicarinata (Gruvel, 1900), lectotype; A, labrum and palp; B, mandible; C, maxilla I; D, maxilla II. Scale bar: 0.1 mm.

FIG. 7. — Altiverruca longicarinata (Gruvel, 1900), lectotype; A, cirrus I; B, cirrus II; C, median article of cirrus VI; D, protopodite of cirrus VI and caudal appendage; E, coxopodite of cirrus VI and penis. Scale bars: 0.2 mm.