Habeastrum strangei, Simone & Cavallari & Salvador, 2020
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publication ID |
https://dx.doi.org/10.3897/zse.96.53880 |
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publication LSID |
lsid:zoobank.org:pub:D5EFEC82-F5FE-41F6-9AE4-889083A9AE8A |
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persistent identifier |
https://treatment.plazi.org/id/3956C96C-C6EB-4044-93C3-52180331AB08 |
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taxon LSID |
lsid:zoobank.org:act:3956C96C-C6EB-4044-93C3-52180331AB08 |
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treatment provided by |
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scientific name |
Habeastrum strangei |
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sp. nov. |
Habeastrum strangei View in CoL sp. nov. Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4
Type material.
Holotype MZSP 151626 (Fig. 1F View Figure 1 ). Paratypes: MZSP 151628 (Fig. 1G View Figure 1 ), MZSP 137432, MZSP 137475, MZSP 147862, MZSP 147863 (all from type locality).
Type locality.
Brazil, Minas Gerais state, Presidente Olegário municipality, Lapa da Fazenda São Bernardo (18°16'37"S, 46°06'46"W).
Additional material.
Brazil. Minas Gerais. Pains municipality: Gruta dos Coralóides (20°20'33.4"S, 45°46'45.7"W), MZSP 106471; Caverna CBA (20°17'43.8"S, 45°47'18.0"W), MZSP 106481. Pedro Leopoldo municipality: unnamed cave (19°37'50"S, 44°00'25"W): MZSP 147121, MZSP 147130, MZSP 147134. Piumhi municipality: unnamed caves (20°20'45"S, 45°50'55"W) MZSP 147445; (20°20'46"S, 45°50'56"W), MZSP 147442, MZSP 147433, MZSP 147462; (20°20'51"S, 45°50'54"W), MZSP 147464; (20°20'57"S, 45°50'45"W), MZSP 147437, MZSP 147438, MZSP 147439, MZSP 147446; (20°20'59"S, 45°50'45"W), MZSP 147467; (20°21'05"S, 45°50'28"W), MZSP 147441; (20°21'06"S, 45°50'21"W), MZSP 147671. Presidente Olegário municipality: Lapa da Juruva (18°19'19"S, 46°04'53"W), MZSP 147864; Lapa do Moacir (18°11'10"S, 46°09'34"W), MZSP 137054, MZSP 137145; Lapa Vereda da Palha (18°15'19"S, 46°07'34"W), MZSP 137181, MZSP 137256, MZSP 150023; Lapa Zé de Sidinei (18°18'06"S, 46°05'41"W), MZSP 137132, MZSP 137143, MZSP 147865.
Etymology.
The specific epithet is given in honor of Dr. Stephen V. Strange, a fictional character from Marvel Comics. Besides being an acknowledgement of one of the greatest Marvel characters, the name also alludes to the weirdness of this dextral diplommatinid species.
Diagnosis.
Spire conical and tall. Teleoconch sculpture consisting of strongly prosocline, markedly raised ribs, more widely spaced than in congeners.
Description.
Shell (Figs 1 View Figure 1 , 2A View Figure 2 ). Shell minute (adult ~2 mm high, ~1 mm wide), conical, ~7 to 7½ whorls; spire elongated. Shell walls translucent, whitish; white soft body easily visible inside. Protoconch (Fig. 2A View Figure 2 ) rounded, smooth, ~2 whorls. Teleoconch sculptured by widely-spaced raised ribs, strongly prosocline; space between ribs ~3 to 5 times the width of a rib; ribs can be more closely-spaced in first teleoconch whorls. Whorl profile rounded, strongly convex. Suture deep, well-marked. Whorls increase steadily in size towards aperture; body whorl does not bulge or change direction of coiling. Aperture circular. Peristome complete, simple and sharp, with only faint deflection over umbilical region. Umbilicus narrow, deep. Operculum (Fig. 1E View Figure 1 ). Thin, corneous, translucent, rounded, paucispiral. Nucleus central. Slightly projected in inner-superior quadrant. Flexiclaudent. Occupying entire aperture.
Head-foot (Fig. 3A, C View Figure 3 ). Totally unpigmented (Fig. 1A-D View Figure 1 ), ~1/3 whorl in length. Head protruded, size ~1/4 of head-foot. Snout (sn) cylindrical, projected downwards; mouth central in ventral surface, longitudinal; length ~1/8 of head foot. Pair of cephalic tentacles (te), narrow, ~1.5 times longer than snout; positioned laterally to slightly dorsally in relation to snout base; gradually tapering up to pointed tip. Eyes present (ey), dark-pigmented; located away from tentacles base, slightly ventrally positioned; each eye mostly duplicated, but with both components very close to each other, so that some specimens (~40%) apparently possess only a single elongated eye. Foot (ft) occupying ~1/2 of head-foot; sole (fs) with thick edges; longitudinal, lateral sulcus separating sole (mesopodium) from dorsal epipodium, flap-like, continuous with opercular pad (oa); epipodium wider, slightly thinner than mesopodium. Columellar muscle (cm) relatively thick, occupying ~1/2 of head-foot, tapering gradually up to blunt, thin tip. Haemocoel (Fig. 3C View Figure 3 ) almost as wide as long, occupying ~3/4 of head-foot; mostly filled by nerve ring and foregut structures. Diaphragm septum (di) small, positioned very posteriorly.
Pallial organs (Figs 3B View Figure 3 , 4A View Figure 4 ). Mantle border (mb) unpigmented, relatively thick, simple. Pallial cavity (py) occupying ~1/2 whorl, no vestige of gill or osphradium; no visible vessels. Genital pallial structures bulging in posterior-right quadrant. Rectum (rt) flanking left edge of genital pallial glands. Anus (an) long, siphoned, ending at some distance posterior to border. Kidney (ki) and pericardium (pc) located on posterior end of cavity.
Visceral mass (Fig. 3B View Figure 3 ). Length 4 to 5 whorls, stomach (st) occupying most of last whorl, ending ~1/3 whorl posterior to pallial cavity. Digestive gland (dg) and gonad white, ~3 whorls posterior to stomach; gonad (go) occupying columellar surface, ~1/3 of digestive gland width.
Circulatory and excretory systems (Fig. 3B View Figure 3 and Fig. 4A View Figure 4 ). Heart (pc) relatively small, ~1/20 pallial cavity’s volume; located in anterior-left side of visceral mass’ anterior end, partly bulging inside pallial cavity. Pulmonary vein (cv) gradually individualizing in postero-left region of pallial cavity, connecting in small auricle, anteriorly located; ventricle of same size as auricle. Kidney (ki) white, entirely solid; length ~1/3 whorl, about as wide as local whorl; nephrostome not seen.
Digestive system (Fig. 3B-F View Figure 3 ). Mouth and snout described above. Buccal mass (Fig. 3D, E View Figure 3 ) occupying ~1/5 of haemocoel volume; located just posteriorly to mouth, inside snout (Fig. 3C View Figure 3 ). Oral tube (ot) with thick muscular walls of mostly longitudinal fibers (mj); its dorsal portion occupies ~1/3 of buccal mass length (Fig. 3E View Figure 3 ), while ventral portion occupies ~1/2 (Fig. 3D View Figure 3 ). Pair of jaw plates (jw) very thin, yellowish, simple; each plate semispherical, located dorso-laterally in transition to oral tube and odontophore, occupying ~1/2 of oral tube’s inner surface. Odontophore (od) occupying ~1/2 of buccal mass volume. Odontophore muscles (Fig. 3D-F View Figure 3 ): mj, pair of jaw and peribuccal muscles, originating in antero-external surface of cartilages, surrounded by m4, running towards anterior region, splaying in oral tube; m4, main pair of dorsal tensor muscles of radula; longitudinal fibers, externally cover cartilages; composed of two layers, internal layer ~1/2 the size of outer layer (Fig. 3F View Figure 3 ); m5, pair of secondary dorsal tensor muscles of radula, narrow and thin; originating in ventral-posterior region of m4, running medially and anteriorly, inserting in ventral surface of radular ribbon, in middle portion of odontophore; m6, horizontal muscle, narrow and thin, connecting both cartilages in their ventral edge, with ~4/5 of cartilages’ length; m10, pair of ventral odontophore protractors, originating in ventral region of mouth; running posteriorly, flanking ventral surface of buccal mass at short distance from its median line, inserting in odontophore close to its limit with oral tube (Fig. 3D, E View Figure 3 ).
Radular sac very long, stored as 4-5 compact whorls located to the right of esophagus in the region preceding buccal mass (Fig. 3C, D View Figure 3 : rs). Radular nucleus (rn) simple, faintly bulging. Radula (Fig. 2B-E View Figure 2 ) taenioglossate, with two marginal teeth and one lateral tooth on each side of central rachidian tooth. Each tooth is composed of a central large claw-like denticle and two smaller denticles on each side (the lateral-most being slightly smaller).
Buccal cavity with pair of wide and low dorsal folds as continuation from jaw plates, gradually diminishing towards esophagus. Pair of buccal ganglia (Fig. 3E View Figure 3 : bg) of considerable size, rounded, each one located laterally, in transition between buccal mass and esophagus. Esophagus (es) as simple continuation of buccal cavity, relatively narrow; pair of dorsal folds from buccal cavity gradually disappear in anterior esophagus, keeping a simple and smooth surface. Pair of lateral esophageal glands (Fig. 3C-E View Figure 3 : eg); right gland ~1/3 haemocoel’s length, slightly broader than esophagus, bulging relatively uniformly along right esophageal wall; left esophageal gland ~1/2 of right gland’s length, but circa twice its width; both esophageal glands hollow inside, walls and inner surface thick and glandular. Posterior esophagus narrow, simple (lacking glands or chambers) (Figs 3B-E View Figure 3 : es), about as long as anterior esophagus; esophageal insertion in stomach small, ventral, ~1/3 of main gastric chamber (Fig. 3B View Figure 3 : es). Stomach (Fig. 3B View Figure 3 : st) size and location described above; its main chamber very wide and long, occupying most of the whorl posterior to kidney. Main gastric chamber lacking internal fold or subchamber; its posterior end suddenly narrows, running posteriorly as a narrow tube along 1.5 whorl (Fig. 3B View Figure 3 : st at right); its posterior end is rounded, unclear if it connects to digestive gland, as it is lying along the gland’s middle region. Anterior region of stomach bluntly tapering; intestine originating in rounded anterior gastric end. Intestine (Fig. 3B View Figure 3 : in) performing a tight loop anteriorly to stomach, suddenly turning left and posteriorly, performing a wide loop dorsally to anterior gastric region; afterwards intestine runs through renal tissue towards anterior region of pallial cavity. In the pallial cavity, rectum (rt) runs through prostate in males (Fig. 3B View Figure 3 ) or to the left of visceral oviduct in females (Fig. 4A View Figure 4 ). Anus (an) long, siphoned (mainly in males), ending posteriorly to mantle border.
Genital system (Fig. 3A, B View Figure 3 and Fig. 4C View Figure 4 ). Male. Testis (Fig. 3B View Figure 3 : go) described above. Vas deferens surging from testis, individualizing at close to posterior region of stomach (Fig. 3B View Figure 3 : superior vd), running close to shell’s columella (with no detectable seminal vesicle) up to posterior end of pallial cavity (Fig. 3B View Figure 3 : inferior vd), inserting in posterior end of prostate. Prostate gland (pt) elliptical, occupying ~1/4 of pallial cavity, mostly solid-glandular; pallial vas deferens (vd) connecting on its ventral surface, penetrating integument on the right side of pallial floor (Fig. 3A View Figure 3 : vd), running straightly to penis’ base. Penis (Fig. 3A View Figure 3 and 4C View Figure 4 ) wide (~1/3 of head-foot width), slightly dorso-ventrally flattened, almost half of head-foot length; penis with uniform width along its length, except for apical region, tapering bluntly. Penis duct (pd) entirely closed (tubular), running along middle penial region, opening in penis tip (pa). Female (Fig. 4A View Figure 4 ). Visceral components similar to those of males. Visceral oviduct very narrow (vo), inserting in postero-right side of pallial oviduct. Pallial oviduct (ov) as single glandular mass, lacking apparent chambers or divisions; walls thick-glandular, ventral and dorsal walls thick. Pallial oviduct occupying ~1/3 of pallial cavity: length ~4/5 of cavity, width ~1/2. Anterior end of pallial oviduct tapering bluntly onto female aperture (ap); aperture simple, turned anteriorly, located posteriorly and to the right of anal base.
Central nervous system (Fig. 4B View Figure 4 ). Nerve ring hypoathroid, relatively large, occupying ~1/6 of haemocoel (Fig. 3C View Figure 3 : pn, ce). Located just posteriorly to buccal mass. Each cerebral ganglion (ce) spherical, with ~1/4 of nerve ring volume. Cerebral commissure narrow, about as wide as each cerebral ganglion. Each pleural (pl) and pedal (pn) ganglion fused with each other, separated only by shallow ventral furrow; each pleuro-pedal ganglion slightly larger than each cerebral ganglion. Both commissures very narrow, of similar length on both sides, ~1.5 times longer than the width of each ganglion.
Distribution.
Caves in central Minas Gerais state, SE Brazil, over an area of ca. 35,000 km² (Fig. 5 View Figure 5 ).
Habitat.
In the caves in Presidente Olegário municipality, this species was found in epigeal environments and in all cave zones (entrance, twilight, and dark zones). Most specimens collected consisted of empty shells, but the good preservation considering their fragility suggests they were not subjected to transport. No precise information was recorded from other municipalities.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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Caenogastropoda |
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