Globuloverruca spongophila gen. nov., sp. nov. a sponge-associated verrucid (Crustacea: Cirripedia: Thoracica) from Easter Island, with discussion on the morphology of the plate tubules Author Young, Paulo S. text Zootaxa 2004 2004-02-03 420 1 1 10 https://biotaxa.org/Zootaxa/article/view/zootaxa.420.1.1 journal article 4883 10.11646/zootaxa.420.1.1 20f5fe8c-3238-4a2d-9fc6-dbfb54a4381d 1175­5334 5027922 17ECCB3F-4ABE-4B1E-A79C-4D0ACB23D609 Globuloverruca spongophila sp. nov. ( Figs 1–5 ) Material examined : Holotype , Easter Island, coll. Louis H. DiSalvo, July/ September 1985 , 50 meters on Microcionidae sponge, probably Echinoclathria sp. (E. Hadju det.) rc: 3.34mm, SIO­BIC C 9426; Paratypes : same locality, several specimens – some left in the sponge, others removed, rc: 1.58–3.46mm, SIO­BIC C 9426; MNRJ 19522. Etymology : From the Greek spongia (sponge) and philos (having an affinity for). Diagnosis : Shell globose. Rostrum and carina strongly convex, apexes curving over opercular plates. Rostro­carinal suture dentate. Scutum and fixed­scutum with projecting adductor ridges. Fixed­tergum with internal projecting ridge overhanging a shallow depression. Opercular plates proportionally small, parallel to base of wall. Cirri I–III strongly unequal, anterior rami one­fourth to one­third length of posterior; articles of posterior rami with combs of denticles. FIGURE 1. Globuloverruca spongophila sp. nov. Holotype. A, top view; B, rostro­carinal view; C, fixed­tergum and fixed­scutum view; D, rostrum and fixed­scutum view. Paratype. E, F, fixed­tergum and fixed­scutum, internal view respectively. Description : Shell ( Fig. 1 ) white, globose, permeated by single rows of tubules deployed between growth lines on all plates; ribs of rostrum and carina interdiar fating along rostro­carinal suture; basal margin not thickened. Rostrum and carina similar in size, strongly convex and with upper portions developed and curving over opercular plates ( Fig. 1a, b ). Rostrum ( Fig. 1a–c ) with surface almost smooth but some parts a little knobbly; apex obtuse; with equal­size, large and flat ribs to rostro­carinal suture forming a strong dentate suture; and with one large radius­like projection directed to carino­scutal suture. Carina ( Fig. 1a–c ) smooth; apex obtuse; ribs extending to rostro­carinal suture, large, flat, equal­size; and with one large radius­like projection directed to fixed­tergal suture. Fixedscutum ( Fig. 1c, f ) with parities smooth, apex projected outward; with a large alar­like projection forming part of rostral suture; fixed scuto­tergal suture straight, with a small radius­like projection; internally, with a projected rounded adductor ridge. Fixed­tergum ( Fig. 1c, e ) similar in size to fixed­scutum, with parities smooth, apex projected outward; with a large alar­like projection forming part of carinal suture; fixed scuto­tergal suture straight, with an alar­like projection on upper part, and a small projection below; internally, largely hollowed out. Base membranous and flat. FIGURE 2. Globuloverruca spongophila sp. nov. Holotype. A, B, tergum and scutum, external view; C, D, tergum and scutum, internal view; E, tergum, lateral view. Opercular plates parallel to base of shell, proportionally small, and partially covered by curved apices of rostrum and carina ( Fig. 1a, d ). Tergum ( Fig. 1a , 2a, c ) trapezoidal, with apico­basal ridge thin and prominent, projecting below lower margin, articular margin folded into two wide ridges above separated by a conspicuous depression; carinal portion smooth. Internally smooth and flat; articular margin irregular. Scutum ( Fig. 1a , 2b, d, e ) smaller than tergum; with one articular ridge; central portion elongate somewhat triangular in shape with scutal border conspicuous and sloping gradually to rostral surface, thin; second ridge twice width of axial ridge paralleling scutal margin; rostral area smooth. Internally, scutum largely hollowed out; upper portion supporting a strong, projected adductor ridge; tergal margin nearly straight; apex projecting outward. FIGURE 3. Globuloverruca spongophila sp. nov. A, labrum; B, palp; C, D, mandible; E, maxilla I; F, maxilla II. Labrum ( Fig. 3a ) with a series of simple sharp teeth and several recurved setulae. Palp ( Fig. 3b ) elongated, with simple setae on inner and distal margins. Mandible ( Fig. 3c, d ) with five obtuse teeth on upper portion and three flattened and acute teeth including inferior angle below, distance between first and second twice distance between second and third, third tooth bifid. Maxilla I ( Fig. 3e ) with lower portion slightly projected; two large stout setae at upper angle, and about 20 small to median­size stout setae below. Maxilla II ( Fig. 3f ) bilobed, lobes separated by shallow concavity; covered by long simple setae, except on concavity. FIGURE 4. Globuloverruca spongophila sp. nov. A,) cirrus I; B, 6 th article of posterior ramus of cirrus I; C, cirrus II; D, 6 th article of posterior ramus of cirrus II. Cirrus I ( Fig. 4a, b ) with unequal rami, anterior ramus one­third length of posterior, covered by numerous simple setae; anterior ramus with slightly protuberant articles; articles of posterior ramus with simple setae along lesser curvature; stout setae on postero­distal margins and combs of short, stiff setae along distal margins of articles. Cirrus II ( Fig. 4c, d ) with unequal rami, anterior ramus one­quarter length of posterior, both rami covered by numerous stout setae; anterior ramus with slightly protuberant articles; articles of posterior ramus similar to those of cirrus I. Cirrus III ( Fig. 5a–c ) with anterior ramus about one­third length of posterior, otherwise similar to cirrus II except distal article of anterior ramus with bipectinate and simple setae and of posterior ramus more slender. Rami of cirri IV– VI ( Fig. 5d ) equal in length, not much longer than longer rami of cirri II and III. Intermediate articles of cirrus VI ( Fig. 5e ) with length about twice width; six pairs of simple setae on anterior margin; none to three fine simple setae on posterior angle. Caudal appendage ( Fig. 5d ) with 11 articles, two and a half times length of protopodite of cirrus VI ; long simple setae on distal margins of articles. Penis ( Fig. 5f ) about twice length of protopodite, distal half clothed with thin setulae. Number of articles of cirri I– VI and caudal appendage is presented in table 1.