Lithoglyptes, Aurivillius, 1892

Kolbasov, Gregory A. & Newman, William A., 2005, Revision of the Lithoglyptidae sensu Tomlinson, 1969 and Lithoglyptes Aurivillius, 1892 (Cirripedia, Acrothoracica,), including a new species from Bermuda, Zootaxa 1013 (1), pp. 35-64 : 41-44

Lithoglyptes s.s. Aurivillius, 1892

( Figs. 1 , 2 )

Diagnosis: Lithoglyptinae having two­segmented caudal appendages plus pedestals, an operculum with a pair of posterior lobes (inconspicuous in L. indicus and L. ivanovi ), opercular bars without long posterior projections or auricles, and a mantle without orificial knob or lateral bars.

Four of the 14 species attributed to Lithoglyptes s.l. are retained in Lithoglyptes s.s. They are the type, L. indicus Aurivillius, 1892 ; L. viatrix Grygier & Newman, 1985 ; L. tectoscrobis Grygier & Newman, 1985 ; and L. ivanovi Kolbasov, 1998 . They are united by a common morphology such as their opercular bars lacking the long projections ( Fig. 1 B, F, H, J ). Such anteriorly or posteriorly hooked projections on the opercular bars are seen in species belonging to the new genera proposed herein ( Figs. 3 A ; 4 A ; 5 A­D, E; 6 A, B). The opercular bars of three of the four species are armed with small, simple teeth and denticles ( Figs. 1 B, H ; 2 A, B ), but in the fourth, L. ivanovi , they bear some bifid teeth ( Fig. 1 J ), a feature seen in the two new genera. The presence of short posterior or "carinal" lobes on the opercular bars is characteristic of L. viatrix and L. tectoscrobis ( Fig. 1 B, F ), the same area in L. indicus and L. ivanovi being marked by a patch of spines ( Fig. 1 H, J ). Lateral bars and/or an orificial knob are completely absent in the armament of the mantle in these four species ( Figs. 1 A, F, H ; 2 A ).

A calcareous, “rostral” plate ( Fig. 1 A, C ), associated with the attachment disk cementing it to the substratum, was described for L. viatrix and L. tectoscrobis ( Grygier & Newman 1985; Kolbasov 2000a). It is possible the other two species also have such a calcareous plate, but they would have to be removed mechanically from the substratum to find out. The caudal appendages of the species of this genus each consist of two segments supported by a pedestal on either side of the anus. The basal segment supports one or two setae and the terminal segment supports a tuft of four or more long, plumose setae at the distal end ( Figs. 1 G, I, K ; 2 G ).

The sac of mature dwarf males, known for some species, may possess lateral projections and a short, thick stalk between the body and the antennules ( Fig. 1 E ).

Surficial ultrastucture of L. viatrix was studied in detail utilizing SEM ( Fig. 2 ). Rows of large multifid scales, common to most Acrothoracica ( Smyth 1986; Kolbasov 1999 a, 2000b, 2000c, 2000d, 2000e; Kolbasov & Høeg 2000), occupy the lateral faces of the opercular area. Occasionally papillae and short setae ( Fig. 2 B, C ) occur between the large multifid scales. The cuticle of the area occupied by an orificial knob, when present, lacks teeth, setae or multifid scales ( Fig. 2 A ). Exposed cuticle of the attachment disk has rounded, transverse lines apparently corresponding to the growth lines of the calcareous plate ( Fig. 2 D ).

In Lithoglyptes s.s., as in all lithoglyptid species studied with SEM ( Kolbasov 1999 a, 2000 a, 2000c, 2000d, 2000e; Kolbasov & Høeg 2000; Kolbasov, unpublished data), the surface of the sheets of cuticle forming the attachment disk are covered with dense, filiform structures arranged in irregular, transverse rows ( Fig. 2 E, F ) and it has been suggested they serve as passages for the secretion of cement ( Kolbasov 1999a; Kolbasov & Høeg 2000).

Distribution: Representatives of the genus are found in the Red Sea, Indian Ocean, Sumatra, Java, Java Sea, Coral Sea, and Hawaii. Depth: subtidal zone ( L. indicus and L. ivanovi ) or at approximately 500 m ( L. viatrix and L. tectoscrobis ).

Hosts: Mainly in scleractinians such as Enallopsammia ampheloides and some undetermined corals. Also in Thais sp. and some undetermined molluscs.

Figures

FIGURE 1. Lithoglyptes s.s. Aurivillius, 1892: A–E – L. viatrix Grygier & Newman, 1985; F, G – L. tectoscrobis Grygier & Newman, 1985; H, I – L. indicus Aurivillius, 1892; J, K – L. ivanovi Kolbasov, 1998. A, C – views of left side; B – left opercular bar of A; D, E – young and mature dwarf males respectively; F – view of left side; G – pedestal of last right cirrus and its caudal appendage; H –view of right side; I – caudal appendage; J – opercular bars viewed from above; K – caudal appendage. (A ­ from Kolbasov, 2000a; C–G – from Grygier & Newman, 1985; H, I – from Tomlinson, 1969; J, K – from Kolbasov, 1998). Abbreviations: ad – attachment disk; bs – basal segment; cp – calcareous plate “rostrum”; crb – cement roofing burrow; lp – lateral projection (wing); ob – opercular bar; pe – pedestal; pl – posterior lobe; rpl – rudimentary (incipient) posterior lobe; rst – rudimentary (incipient) stalk; ts – terminal segment. Scale bars in µm.

FIGURE 2. Lithoglyptes s.s. Aurivillius, 1892: L. viatrix Grygier & Newman, 1985. A – anterior portion of operculum, oblique view; B – lateral surface of operculum; C – opercular papilla; D – attachment disk, lower part; E – cuticle of attachment disk, lower part; F – cuticle of attachment disk, upper part; G – caudal appendages. (D, E, F – from Kolbasov, 2000a). Abbreviations: bs – basal segment; ms – massive multifid scales; ob – opercular bar; oka – orificial knob area; op – opercular papillae; pe – pedestal; ts – terminal segment. Scale bars in µm.

FIGURE 3. Auritoglyptes gen. nov.: A. bicornis (Aurivillius, 1892). A – viewed from right side; B – mandible; C – mandibular palp; D – maxillule; E – caudal appendage; F – dwarf male. (A, E, F – from Kolbasov, 2000e). Abbreviations: ad – attachment disk; as – apertural slit; cc – comb collar; lp – lateral projection (wing); obp – opercular bar, posterior projection; oka – orificial knob area; sp – long, articulated posterior setose process (“auricle”); st – stalk. Scale bars in µm.

FIGURE 4. Auritoglyptes gen. nov.: A. bicornis (Aurivillius, 1892). A, B – posterior and anterior portions of operculum respectively; C – surface of an auricle; D – opercular papilla; E – massive multifid scales; F – surface of orificial knob area; G – cuticle of attachment disk; H – flexible cuticular extensions of attachment disk (G) enlarged; I – dwarf male, apertural slit; J – dwarf male, base of stalk; K – dwarf male, rows of fringes or denticles on the middle part of body (all photos from Kolbasov, 2000e). Abbreviations: as – apertural slit; cc – comb collar; ms – massive multifid scales; obp – opercular bar, posterior projection; op – opercular papillae; sp – auricle; spp –papillae of an auricle; st – stalk. Scale bars in µm.

FIGURE 5. Armatoglyptes gen. nov.: A, B, F – A. habei (Tomlinson, 1963); C, G – A. echinoideus (Kolbasov, 2000); D – A. scamborachis (Tomlinson, 1969); E, I, J – A. wilsoni (Tomlinson, 1969); H – A. mitis (Tomlinson, 1969). A – view of left side; B – detail of right opercular area; C – right opercular area; D – view of right side; E –view of left side; F, G – caudal appendages; H – dwarf male; I, J – dwarf males (Wake & Koror, respectively). (A – from Kolbasov, 2000a; C, G – from Kolbasov, 2000f; D, E, I, J – from Tomlinson, 1969; H – from Kolbasov, 2002). Abbreviations: a1 – antennules; ad – attachment disk; as – apertural slit; cc – comb collar; cp – calcareous plate; lb – lateral bar; m – dwarf male; mp – mouth parts; ob – opercular bars; obp – opercular bar, posterior projection; ok – orificial knob; oka – orificial knob area. Scale bars in µm.