Quantula striata (Gray, 1834)
“1st den Weichtheilen nach nicht nur naninoides, sondern in der That eine wahre Nanina, indem sich am hinteren Ende des Fusses eine deutlich schief abgeflachte länglichovale Stelle, die Oeffnung der Schleimdrüse enthaltend, findet. Singapore, in den nächsten Umgebungen der Stadt häufig, von Benson, Hombron und Jacquinot, F. Jagor und mir gesammelt. Pulo Pinang, Museum der ostmdischen Compagnie in London. Wechselt bedeutend, sowohl in absoluter Grösse, als in relativer Erhebung des Gewindes, wie auch im hellen oder dunklen Ton der Färbung der Oberseite. In der Jugend ist die Schale scharf kantig. Dass die oben citirte H. isabella, nicht zu verwechseln mit der ceylonesischen N. isabellina Pfr,, hieher gehört, ist mir nach Abbilduno-und Fundort unzweifelhaft, obwohl Pfeiffer beide in zwei verschiedene Paragraphen setzt. Helix orientalis Gray kann ich nach Beschreibung und Abbildung bei Reeve nicht von dieser striata unterscheiden. Helix celebensis Pfr. Journ. couch. X. 1862 p. 229, pl. 10., fig. 3. ist ebenfalls der striata sehr älmlich, aber etwas höher, in den Umrissen an rareguttata erinnernd, Durchmesser 27½- Höhe 22 Mill. Als Vaterland wird »Rhwo« auf Celebes angegeben, nach Gassies in Bordeaux; einen solch barbarischen Namen oder irgend einen ähnlichen finde ich auf keiner Karte und in keiner Beschreibung dieser Insel; dagegen gibt es unweit Singapore eine noch holländische Insel, deren Namen bald Riouw, bald Khio geschrieben wird, und in Anbetracht der nahen Verwandtschaft mit striata neige ich mich der Vermuthung zu, dass diese gemeint ist. Dann wäre der Name celebensis zu streichen. Vielleicht ist sie überhaupt nur als Varietät von striata zu betrachten.” (Martens, 1867)
Notes on Helix crossei - “L'Helix crossei est communément répandue, comme l'espèce précédente, sur les terres basses du Cambodje et do la Cochinchine. C'est une des premières coquilles qui aient été rapportées de Saigon à la suite de l'expédition française, et il y en a peu qui aient fourni jusqu à présent des elements d'étude aussi complets. La couleur de cette Hélice rappelle généralement celle de la cannelle (cinnamomea); cependant elle peut varier, du jaune paille très pâle au brun rouge tirant sur le marron. Lorsque la spire atteint un certain degré de convexité, le dernier tour est simplement anguleux, c'est le type; mais quand elle est déprimée, l'angle périphérial se prononce davantage et devient une careen plus ou moins tranchante, c'est la variété. M. Crosse a fait connaître celle-ci sous lo nom de weinkauffiana. Il me paraît bien difficile d'accorder une valeur spécifique à une forme qui se rattache aussi étroitement au type par ses caractères essentiels et sa physionomie. Quant aux caractères secondaires, tels que la dépression de la spire et la carène qui en dérive, il suffit de comparer un certain nombre de sujets pour constater la progression graduelle et l'enchaînement de ces modifications qui influent, en memo temps, sur la capacité de l'ouverture; celle-ci devieut effectivement plus large lorsque le dernier tour est plus renflé. En un mot, les particularités sur lesquelles est fondée l’Hélix weinkauffiana me paraissent rentrer dans les limites que l'on peut assignera la variabilité de l'espèce. L’Helix crossei est sujette à des écarts de dimension de 12 à 13 millimètres ; les plus petits individus que j'aie vus atteignaient 21 millimètres, et les plus grands 34. Malgré cette variabilité dans la taille, l'espèce est toujours parfaitement reconnaissable.” (Morelet, 1875)
Notes on Helix naninoides - “La synonymie un peu confuse de cette coquille a été rectifiée par Pfeiffer dans le cinquième volume de sa Monographie que l'on peut consulter. C'est avec doute que ce savant y fait rentrer l’H. isabella du Voyage au Pôle Sud; mais l'examen des types conservés au Muséum de Paris ne laisse aucune incertitude sur l'identité des deux espèces. J'ai sous les yeux une variété major de l’H. naninoides, provenant de Poulo-Condor, et mesurant 31 millimètres de diamètre sur 28 de bailleur; du reste, à l'exception d'une particularité dont je vais parler, elle concorde parfaitement avec les individus de la presqu'île malaise. Celte particularité consiste en un épaississement du bord columellaire qui se traduit, vers le milieu, en une callosité légè rement anguleuse. On retrouve quelquefois le même épaississement, bien qu'à un moindre degré, chez l’H. crossei, qui se rapproche beaucoup de l'H. naninoides, et qui n'en diffère mémo que par sa dépression et son péristome plus calleux; il ne faut voir probablement ici qu'un simple résultat de l'âge.” (Morelet, 1875)
“Tail abruptly truncate, gland relatively rather small, surrounded with a broad swollen margin; it is evidently congeneric with N. ligulata, the animal of which it closely resembles.” (Nevill, 1878)
Note on Nanina naninoides – “This species varies in having distinct concentric striae or being without them. Colour brownish or nearly white; periphery more or less distinctly keeled.” (Tenison-Wood, 1888)
“The author compares his form with H. crossei and H. weinkauffiana; I think, however, that it will prove to be a variety of the common species of Singapore and the Straits generally, Nanina striata, Gray, or Helix naninoides, Benson.” (Möllendorff, 1891)
Gray (1834) original descriptions on Nanina striata – “Nan. Testâ solidiusculâ, subpellucidâ, albidâ; periostracâ tenui, olivaeâ; spira convexiusculâ, confertim transverse striatâ; anfractu ultimo antice sublaevi.”
Benson (1842) original descriptions on Helix naninoides – “Testâ solidiusculâ, subdiscoideâ, supernè radiatim tenuiter striatâ, infra striis laevigatis, distantibus; spirâ depresso-conoideâ, apice obtusato, planulato; aperturâ transversè lunatâ, labro obtuso, crasso, infrà subreflexo.”
Pfeiffer (1848) descriptions on Helix naninoides – “T. perforate, orbiculato-convexa, soliduscula, pallide fulva, superne distincte et confertim striata, lineis concentricis, saepe obsoletis subdecussata, basi sublaeviagata, distanter striatula; spira depresso-conoidea, apice obtuse; anfr. 6 vix convexiusculi, ultimus subangulatus, medio impressus; aperture transverse lunaris; perist. rectum, obtusum, subinerassatum, ad perforationem apertam brevissime reflexum.”
Pfeiffer (1862) original descriptions on Helix crossei – “T. pervie perforata, turbinata, solidula, confertim arcuato-costulata (lineis spiralibus obsolète decussatula), parum. nitens, carneo-fulvida; spira conoidea, obtusula; anfr. 6½ convexiusculi, regulariter accrescentes, ultimus carinatus, non descendens, subtus parum convexus, medio laevigatus, albidus; apertura parum obliqua, subangulato- lunaris, intus margaritacea; perist. rectum, marginibus subparallelis, columellari calloso-incrassato, juxta perforationem vix dilalato.”
Pfeiffer (1862) French descriptions on Helix crossei – “Coquille perforée, turbinée, assez solide, munie de petites côtes arquées et serrées, peu brillante et d'un fauve carnéolé; spire conoïde, légèrement obtuse; tours de spire au nombre de 6½, légèrement convexes et s'accroissant régulièrement, dernier tour caréné, non descendant, médiocrement convexe et blanchâire en dessous, lisse à sa partie médiane; ouverture médiocrement oblique, subanguleuse, d'un blanc nacré à l'intérieur; péristome droit, à bords subparallèles, bord columellaire épaissi, à peine dilaté dans le voisinage de la perforation.” (Pfeiffer, 1862)
Martens (1867) descriptions on Nanina striata – “Testa pcrforata, orbiculato-convexa, solidiuscula, supra distincte et confertim striata, lineis spiralibus rariusculis subdecussata, pallide castanea vel fulvo-flavescens, infra striatula, albida, nitida; spira depresse-conoidea; anfr. 6, convexiusculi, ultimus subangulatus, antice paulisper descendens: apertura diagonalis, pro ratione generic parva, lunato-semielliptica; peristoma rectum, obtusum, sat crassum, margine basali et columellari stricto fere horizontali, ad insertionem brevissime reflexiusculo.”
Morgan (1885) original descriptions on Hemiplecta leechi – “Hemiplecta testa dextrorsa cornea, translucida, ad aperturam albida, subglobulosa, vix umbilicata 5-6 anfractibus composita, paralleliter lineis aetatis ornata eostis laevissimis in extremis anfractibus et crassioribus in primis; sutura lineata, aperture obliqua, elliptica, ante ultimo anfractu largiter incisa; peristomate recto; labro columellari loeviter ad umbilicum reflexo.”
Morgan (1885) French descriptions on Hemiplecta leechi – “Coquille. - Dextre, subglobuleuse, à peine ombiliquée, compose de 5 cà 6 tours de spire, ornée parallèlement aux ligues d'accroissement de stries très fines, plus fortes à la partie supérieure des tours qu'à la base; suture linéaire très marquée; ouverture ovale oblique, largement échancrée par l'avant-dernier tour de spire; péristome légèrement réfléchi vers l'ombilic. Dans son jeune âge cette coquille est assez fortement carénée, mais elle cesse de l'être à l'état adulte. Couleur. — Cette coquille est d'un brun corné à la partie supérieure, blanche à la base et principalement à l'ombilic et jaune aux environs du bord externe. Elle est translucide et souvent même très transparente. Son ouverture est de couleur variable, blanche chez quelques individus, elle devient rose ou violette chez d'autres.”
Tryon (1886) descriptions on Nanina (Xesta) naninoides – “Perforate, rather solid, closely distinctly striated above, obsoletely decussated by concentric lines, base smoother, distantly striulate; light orange-brown, or yellowish corneous, whitish and more shining below; whorls 6.”
Gross Anatomy – “The small snails (shell diameter 13-1 6 mm; N = 4) had small, poorly developed reproductive systems when compared to the large snails (shell diameter = 20 mm, N = 9). The small snail reproductive system was relatively small and undeveloped compared to that of the large snails. The snail with a "visible" luminescent organ had an expanded dart gland (lobes were separated and expanded), a swollen dart gland duct, and a dart in the dart sac. These features were also seen in four other large snails that had a luminescent organ. The snail with a "non-visible" luminescent organ had a more compact dart gland (the lobes were tightly folded together), a narrower dart gland duct, and no dart in the dart sac. These features were also found in two additional snails with a "non-visible" luminescent organ. The spermoviduct of the snail with the "visible" luminescent organ was swollen in comparison to the snail with no luminescent organ. Both animals had a reddish spermatheca.” (Copeland & Daston, 1993b)
Microscopic Anatomy – “Ovotestis: The ovotestis of all of the large snails (N = 2 with "visible" luminescent organ and N = 2 with "non-visible" luminescent organ) contained mature spermatozoa. Mature sperm were identified by the appearance of the axoneme of the flagellum in cross section. The Sertoli cells are the largest of the four general cell types found in the acinus (sperm, oocytes, follicle cells, and Sertoli cells) (Tompa, 1984). Normally, stylommatophoran oocytes range from 50-200 μ (Tompa, 1984). No cells of that size were found in the ovotestis.” (Copeland & Daston, 1993b)
Luminescent Organ – “Organ of Haneda: All luminescent organs (N = 2 large-sized snails with "visible," N = 2 large-sized snails with "non-visible," and N = 2 small-sized snails with "visible," luminescent organs) showed an integument of dorsal ciliated epithelium, a ventral simple squamous epithelium, and large granular photocytes surrounded by connective fibers. Photocytes were recognized by the large secretory droplets that comprised much of the cytoplasm. The size and appearance of the droplets varied among the different snail groups. The average droplet size for the large snails with a "visible" luminescent organ was 0.14 μm ± 0.02 S.D. (N = 15) and 2.4 μm ± 0.56 S.D. (N = 15) for large snails with a "non-visible" luminescent organ. For small snails, the average droplet size was 5.8 μm ±2.15 S.D. (N = 15). The substance in the droplets of the large snails with "visible" luminescent organs was homogeneous and was only slightly electrondense, whereas the material in the droplets of the large snails with "non-visible" luminescent organs contained a granular substance. The substance in the droplets of the small-sized snails was homogeneous and electron dense. Structures that have the ultrastructural characteristics of axon terminals were found between and directly beneath the integumentary epithelium in one large snail with a "visible" luminescent organ. Connective fibers were also found that show the characteristic striated feature of collagen in longitudinal section at high magnification. When dissected, the organ of Haneda was shaped like a flattened discus. It was yellowish in appearance, and consisted of an epithelial integument which surrounded photocytes.” (Copeland & Daston, 1993b)
Flash Types and Patterns – “Adult Flash Types: The type of luminescence spontaneously produced by adult D. striata ranges from a discrete bright flash to a very weak low intensity glow-like flash. Time from baseline until flash peak was variable but less than one second. The flashes of seven adult snails were viewed. They flashed continuously (no interflash interval greater then 60 sec) for 19-45 minutes within the total one hour recording period (first 10 minutes ignored). These flashes, when viewed directly or monitored indirectly via the photomultiplier, were categorized as simple flashes (with a single peak), which were symmetrical or asymmetrical, and modulated flashes (with more than one peak). In modulated flashes, an intensity modulation produced a pulsation of light. Sometimes, the pulsation could be resolved into two discrete flashes. Flashes with three or four peaks occurred, but these were rare (< 1%) in adult snails. Both simple and modulated flashes in adult D. striata last from 0.5 to 6 seconds, although there was a tendency for simple flashes to be shorter than modulated flashes. All adult snails showed both simple and modulated flashes, although the ratio of simple: modulated flashes varied from about 1:1 to 2:1 in the seven snails viewed. Usually, several flashes of one kind would be followed by several flashes of the other kind, but the two types of flashes (simple or modulated) could be interspersed. No obvious correlation was seen between snail behaviour and flash type. The interflash interval for these individuals varied between 2-80 seconds, with a mean interflash interval of 18.0 ± 1.2 S.D. sec. The adult flash was yellow-green in color and weak in intensity. Indeed, some dark adaptation was necessary before an observer could easily see the flash. (When compared by eye to the flash of the firefly Pteroptyx mallacae, the flash of D. striata was considerably weaker in intensity.) However, during the most intense flashes, the entire anterior part of the snail was illuminated. Because any movement of the head-foot, which contains the luminescent organ of D. striata, could create the illusion of multiple peaks when the luminescent organ was viewed by a stationary photomultiplier, on several occasions a flashing adult D. striata was viewed using weak red backlighting to produce a silhouette. When modulated flashes occurred, the head-foot was continuously extended against the substrate. Thus, the modulated flashes could not have occurred because a continuously glowing luminescent organ was moved in and out of the shell like a shutter, something that has been found with other luminescent organs in other animals (Herring, 1978). Juvenile Flash Types: Juvenile flash types in D. striata were similar to adult flash types: simple and modulated flashes occurred, as did glows. As in the adult, the color of the flash was yellow-green, but the flash was considerably brighter to the eye. Little dark adaptation was necessary to view juvenile snail flashes, and many of the flashes appeared to the eye to contain pulsations. In fact, the juvenile flash could be so bright and had such a range of intensities when compared to the adult flash that it was difficult to obtain complete records from all the juvenile snails tested (N = 10) because many of the flashes from some snails saturated the photomultiplier tube, thus preventing multiple flashes from being recorded. They flashed continuously (no interflash interval greater than 60 seconds) for 18 to 30 minutes. Simple flashes lasted 0.5-2.5 seconds and modulated flashes lasted 0.5-5.5 seconds. The difference between simple and modulated flashes was significant (t-test, p < 0.02). The ratio of simple: modulated flashes was less than 1:2 for one snail and 1:7 for the other snail. Many modulated flashes had three peaks or more (12-41%). The interflash interval from the two juvenile snails varied between 2 and 50 seconds. Mean interflash interval (N= 2) was 9.8 ± 0.5 S.D. sec.” (Copeland & Daston, 1993a)
Nanina striata – “Axis 9, diam. 15 lin.” (Gray, 1834); Helix naninoides – “Diam. Maj. 25, min. 22, alt. 13 mill. β – Major. Diam. maj. 33, min. 29, alt. 20 mill” (Pfeiffer, 1848); Nanina striata – “Diam. maj. 24-28, min. 20½-23½, alt. 15-18: apert. long. 13-15½, lat. 10-11½ Mill.” (Martens, 1867); Helix crossei “Diam. maj. 28½, min. 25, alt. 17 mill.” (Pfeiffer, 1862); Hemiplecta leechi “Dimensions. - Largeur, 26 mm; hauteur du cône spiral, 8 mm; hauteur totale, 16 mm; longueur de l'ouverture, 13 mm; largeur de l'ouverture, 11 mm.” (Morgan, 1885); Nanina (Xesta) naninoides – “Diam. 25, alt. 13 mill.” (Tryon, 1886)
Type locality –Helix naninoides “Singapore” (Benson, 1842); Helix crossei “Siam” (Pfeiffer, 1862); Hemiplecta leechi “royaume de Pérak” (Morgan, 1885)
Other localities – Helix naninoides “rarius in insula Chusan” (Pfeiffer, 1848); “Territorio di Sarawak” leg. Doria and Beccari (Issel, 1874); “Cambodja, Indo-Chine” (Morelet, 1875); Nanina crossei “Sinkip I.” coll. J. Wood-Mason (Nevill, 1878); Nanina crossei “Singapore” coll. F. Stoliczka & J. Irving (Nevill, 1878); “Salanga” (Martens, 1883); “Prang, on the Malay Peninsula.” Leg. W. L. Abbott (Dall, 1897)