Weltnerium hydrozoaphilum, Young, 2000

Young, Paulo S., 2000, Cirripedia Thoracica (Crustacea) collected during the “ Campagne de La Calypso (1961 - 1962) ” from the Atlantic shelf of South America, Zoosystema 22 (1), pp. 85-100 : 90-97

publication ID	https://doi.org/ 10.5281/zenodo.5395280
publication LSID	lsid:zoobank.org:pub:6D2F4BB8-4A20-43A3-BDCD-C3877304A6C7
persistent identifier	https://treatment.plazi.org/id/038F6057-FF84-DE54-78D3-26305074FB14
treatment provided by	Marcus
scientific name	Weltnerium hydrozoaphilum
status	sp. nov.

Treatment

Weltnerium hydrozoaphilum n. sp. ( Figs 2 View FIG A-C; 3A-I)

TYPE MATERIAL. — Holotype: stn 57, 12°56,4’S, 38°33,5’W, 18 m, on hydrozoan stem, 24. XI.1961, tl 71 mm cl 47 mm (MNHN Ci2802). Paratypes: same locality, 3 specimens, tl 32 mm cl 22 mm, tl? cl 34 mm, tl 65 mm cl 44 mm (MNHN Ci2718, MNRJ 12926).

ETYMOLOGY. — From the Greek philo (love, having an affinity for), preceded by hydrozoa, referring to the colony where the specimens were attached.

DIAGNOSIS. — Capitular cuticle with a few scattered clusters of setae. Carina with subapical umbo. Inframedian latus pentagonal, with subapical umbo. Carino-latus with umbo at lower third of carinal margin.

DESCRIPTION

Capitulum ( Fig. 2A View FIG ) flattened, length less than twice width, covered by thin cuticle, with occludent margin straight and carinal margin convex. Cuticle with few clusters of setae irregularly dispersed on capitulum. Plates with few conspicuous growth lines.

Tergum ( Fig. 2A View FIG ) triangular with its surface area greater than scutum, with lateral thickening near apex of carina. Basal margin convex. Carinal margin slightly convex. Occludent margin straight. Apex not recurved.

Scutum ( Fig. 2A View FIG ) convex, trapezoidal. Basal margin straight, curving to lateral margin which is slightly concave at apical portion. Tergal margin straight, only curving at apex. Occludent margin straight but upper portion convex. Apex recurved, superimposed on tergum.

Carina ( Fig. 2A, B View FIG ) regularly arched and thickened, umbo subapical. Tectum convex at upper portion and flat basally; basal margin triangular.

Upper-latus ( Fig. 2A View FIG ) pentagonal, symmetrical, with umbo usually slightly projecting above surface of capitulum; umbo displaced from apical to subapical position by thickened edge at scutal and tergal margins. All margins straight, except the concave scutal margin.

Carino-latus ( Fig. 2A View FIG ) high, one time and a half its width, umbo at lower third of carinal margin and below base of carina, not projecting outward. Carino-latera in contact with one another, but not interdigitating below carina ( Fig. 2B View FIG ).

Inframedian latus ( Fig. 2A View FIG ) large, pentagonal, with umbo subapical.

Rostro-latus ( Fig. 2A View FIG ) wider than high, with an apico-basal ridge. Lateral margin convex. Upper and basal margins straight and slightly diverging. Rostrum ( Fig. 2C View FIG ) large, triangular with an alar projection on each side directed beneath carinolatera.

Peduncle ( Fig. 2A View FIG ) short, one half length of capitulum, covered sparsely by lengthened scales arranged in basic pattern of eight verical tiers.

Labrum ( Fig. 3A View FIG ) bullate, with several denticles, most of them multifid. Palp ( Fig. 3B View FIG ) small, acuminate with a few thin setae on its margins. Mandible ( Fig. 3C View FIG ) with three acute teeth; second and third with subsidiary cusps; lower angle denticulate. Maxilla I ( Fig. 3D View FIG ) with straight anterior border, lower portion not projecting, two large spines at apical angle and five moderate, one large and nine moderate to small spines directed downwards. Maxilla II ( Fig. 3E View FIG ), with anterior margin having median notch, posterior margin convex; covered by numerous large and simple setae, absent on anterior notch; papilla of maxillary gland short, not pronounced.

Cirrus I ( Fig. 3F View FIG ) anterior ramus shorter, with subequal rami; former with protuberant articles; both rami covered by numerous long, simple setae. Cirrus II to VI with equal rami. Median article of cirrus VI ( Fig. 3G View FIG ) four times and a half longer than wide, five pairs of setae on anterior margin and one to three setae on posterio-distal angle.

Caudal appendage ( Fig. 3H View FIG ) with three articles, length less than basal article of cirrus VI; articles with few setae on distal margins. Number of articles of cirri I-VI and caudal appendage is present- ed in Table 3. Penis long, covered with thin setae. ( Fig. 4A, E View FIG ) parallel to basis, size reduced, one half rostro-carinal diameter. Surface of opercular plates and shell permeated by several rows of uncalcified tubes paralleling to growth lines in small specimens, calcified closed in larger ones. Basal margin of wall not inflected.

Fixed tergum ( Fig. 4A, E View FIG ) smaller than fixedscutum, marginal apex thickened; alar projections absent, sutures essentially straight.

Fixed scutum ( Fig. 4A, B, E View FIG ) nearly rectangular, upper surface turned toward rostral margin of scutum; sutural areas simple and nearly straight. Internally, with well-developed myophore parallel to basis.

Carina ( Fig. 4A, E View FIG ) smaller than rostrum, welldeveloped ridge area at suture with rostrum but forming only shallow depressions between ridges, three to four interlocking teeth, ridges decreasing slightly in size from apex to basis; suture with fixed tergum straight.

Rostrum ( Fig. 4A, E View FIG ) with well-developed ridged area at suture with carina, but forming only shallow depressions between ridges, three to four interlocking teeth, ridges decreasing slightly in size from apex to basis; suture with fixed scutum nearly smooth.

Opercular plates with growth lines conspicuous, but not projecting. Tergum ( Fig. 4A, C, E View FIG ) larger than scutum, nearly quadrangular, with three articular ridges; axial (apico-basal) ridge elevated, conspicuous at both sides, thinner than second, second ridge low and wide, third small, very narrow; with one groove between second and third ridges; without ridges at carinal area. Internally, surface flat, some sealed tubes visible; scutal margin slightly sinuous.

Scutum ( Fig. 4A, D, E View FIG ) with two low articular ridges, axial ridge very low, thin, sloping continuously to rostral area; second ridge very narrow, no ridges at rostral area; greater width of plate less than one half scutum height. Internally, surface with some sealed tubes visible, adductor ridge conspicuous; tergal margin sinuous; occludent margin thickened.

Labrum ( Fig. 5A View FIG ) with row of obtuse teeth. Palp ( Fig. 5A View FIG ) paddle-like, simple setae at inner margin. Mandible ( Fig. 5B View FIG ) with three distinct teeth, second and third serrated on apical margin, low obtuse denticles on inferior angle. Maxilla I ( Fig. 5C View FIG ) with lower portion of anterior margin protruding; upper portion of anterior margin with two large spines, followed by 12-16 intermediate to small spines. Maxilla II ( Fig. 5D View FIG ) bilobed, with numerous simple setae along its margins.

Cirrus I ( Fig. 6A View FIG ) with unequal rami; anterior ramus with protuberant articles, two fifth of the length of posterior ramus, covered by numerous simple setae; posterior ramus with slightly protuberant articles. Cirrus II ( Fig. 6B View FIG ) with unequal rami, anterior ramus about one fourth of the length of posterior, both rami covered by numerous simple setae. Cirrus III ( Fig. 6C View FIG ) also with unequal rami, anterior ramus about one third of the length of posterior, both rami covered by numerous simple setae, distal articles of anterior ramus with few bipectinate setae. Cirri IV to VI with equal rami; intermediate articles ( Fig. 5E View FIG ) with four pairs of setae on anterior margin, one or two setae on posterior angle, length about three times width; large setae six times width of article. Caudal appendages ( Fig. 6D View FIG ) of 9-10 articles, three times length of coxopodite of cirrus VI; articles covered by numerous simple setae at distal margins. Number of articles of cirri I-VI and caudal appendage is presented in Table 4. Penis ( Fig. 6D View FIG ) short, clothed with thin setulae.

REMARKS

Young (1998) revised the genera of Verrucidae . Only four species were assigned to Verruca s.s.: V. stroemia (Müller, 1776) (type species); V. spengleri Darwin, 1854 ; V. laevigata (Sowerby, 1827) , and V. cookei Pilsbry, 1927 . Buckeridge (1997) described V. jago which is here assigned to this group. Thus Verruca minuta n. sp. is the sixth species included in Verruca s.s. All of the species have a low or depressed wall and the proportionately small opercular plates are parallel to the basis, the umbones of the carina and rostrum are marginal, without secondary ridges, and the myophore is well-developed and projects parallel to the basis.

V. minuta n. sp. differs from V. stroemia , V. laevigata and V. jago in having an adductor ridge on the movable scutum. V. spengleri and V. cookei are very similar to V. minuta n. sp. in the movable scutum having a characteristic adductor ridge.

V. cookei was described briefly by Pilsbry (1927) based on specimens from Hawaii, but the movable scutum of this species has three articular ridges, its adductor ridge is longer and the anteri- or margins of the posterior articles of cirrus VI have five pairs of setae.

V. spengleri was originally described from Madeira Island by Darwin (1854) and subsequently recorded from the Azores (Young 1998). The movable scutum has three articular ridges, the occludent margin protrudes in the middle with a relative shorter basal margin, and the carina and rostrum have a suture forming deep depressions between ridges.

All of the species are usually small and are found in shallow waters, mostly on the continental shelf. Verruca minuta n. sp. occurs between 37 and 62 m, from 13 to 20°S. This species was probably overlooked previously, due to its small size. The specimens were not attached to the substrate. Both Revizee specimens were found when sorting samples taken from washes of calcareous algae nodules. V. minuta n. sp. probably attaches on this calcareous substrate, which is common on the tropical Brazilian continental shelf.