Skip to main content

Landouria bella and Landouria monodon (Camaenidae Pilsbry 1895), new species from Thailand

NEWS - Researchers described the genus Landouria (Godwin-Austen, 1918) and identified two new species, Landouria bella and Landouria monodon. The team from Chaiyaphum Rajabhat University in Chaiyaphum and Mahasarakham University in Maha Sarakham noted that the two species were distinct from each other in the genus.

Landouria bella and Landouria monodon (Camaenidae Pilsbry 1895), new species from Thailand 1

Hirano et al. (2014) suggested that Landouria is a junior synonym of Aegista. In fact, a unique characteristic shared by all Landouria members in Thailand is the absence of a dart sac and a stimulatory organ, a combination of characters that are considered to define the family Camaenidae.

Benchawan Nahok and team showed that Landouria and Aegista are two distinct genera. Landouria has a small, compressed shell, a wide, open umbilicus, and the presence of flagella of various shapes. To date, more than 50 species have been recorded in the genus.

L. bella was collected from isolated limestone hills in Ratchaburi and Phetchaburi provinces, western Thailand. Small, concave-rounded shell without peripheral keel, presence of small and thin lamellae on the columellar side of the inner aperture, long, cylindrical, bent distally flagellum, short penis with rounded verge, short and thick free oviduct and vagina.



L. monodon was collected from sandstone hills in Kalasin Province, northeastern Thailand. The shell is concave-conical with blunt peripheral keel, thick prominent lamellae on the columellar side of the inner aperture, short, finger-shaped, bent distally flagellum, long penis with small and short verge.

Landouria bella and Landouria monodon (Camaenidae Pilsbry 1895), new species from Thailand 2

L. bella differs from all other species from Thailand by its concave and rounded shell. Other Thai Landouria species usually have slightly angular to prominent keels on the edges, as seen in L. monodon. The presence of small and thin columellar lamellae on the inner aperture of L. bella resembles that of L. monodon, but is more prominent.

Original research

Nahok B, Chanlabut U, Tumpeesuwan S, Tumpeesuwan C (2024) Two new species of Landouria Godwin-Austen, 1918 (Gastropoda, Camaenidae) from Thailand, with a key to Thai species. ZooKeys 1208: 347-362. DOI:10.3897/zookeys.1208.117056

Popular Posts

False ashoka (Monoon longifolium)

False ashoka ( Monoon longifolium ) is a plant species in the Annonaceae, a small tree, evergreen, up to more than 20 meters high, symmetrical pyramidal with pendulous branches, hardwood, easy to grow and very adaptive. M. longifolium has long narrow lanceolate leaves with wavy edges, 25 cm long, 6 cm wide, copper brown pigmentation but over time becomes bright green and finally dark green. Pale green flowers resemble delicate stars. The flowering period is usually 2-3 weeks. Fruits in 10-20 pieces, round, up to 2 cm wide, green but turn purple or black when ripe. Trees are used to filter air pollution. Leaves are used for decorative decoration during festivals. Trees are easily pruned into various shapes and maintained in the required size. Flexible, straight and light rods are used in making sailing ship masts. Wood for making pencils, boxes and matches. Seed oil has anti-oxidant, anti-lipooxygenase and antimicrobial activity. Kingdom: Plantae Phylum: Tracheophyta Subphylum: An...

Kemadih (Schultesianthus coriaceus)

Kemadih ( Schultesianthus coriaceus ) is a species of plant in the Solanaceae family. It grows as a climber and covers host trees. It is a perennial, multi-branched, hardwood plant with hard, brown bark and dark green young bark. S. coriaceus has thick leaves, 15 cm long and 8 cm wide. A central vein is linear, with a pointed tip and base. The upper surface is dark green and the lower surface is bright green. The petiole is 3 cm long. The flowers are fan-shaped with 5 inflorescences. The base is narrow, whitish-yellow or bright green, and 8 cm wide. Four inflorescences with brownish-white tips and one inflorescence with a green tip grow in the center. The fruit is green, 3.5 cm long, and the stalk is 2 cm long. Kingdom: Plantae Phylum: Tracheophyta Subphylum: Angiospermae Class: Magnoliopsida Order: Solanales Family: Solanaceae Subfamily: Solanoideae Tribe: Solandreae Genus: Schultesianthus Species: Schultesianthus coriaceus

Black potato (Coleus rotundifolius)

Black potato ( Coleus rotundifolius ) is a species of plant in Lamiaceae, herbaceous, fibrous roots and tubers, erect and slightly creeping stems, quadrangular, thick, and slightly odorous. Single leaves, thick, membranous, opposite and alternate. Leaves are oval, dark green and shiny on the upper side, bright green on the lower side. Up to 5 cm long, up to 4 cm wide, slightly hairy and pinnate leaf veins. Leaf stalks up to 4 cm long. Small, purple flowers. Star-shaped petals, lip-shaped crown, dark to light purple with a slightly curved tube shape. Flowering from February-August. Small tubers, brown and white flesh and tuber length 2-4 cm. Kingdom: Plantae Phylum: Tracheophyta Subphylum: Angiospermae Class: Magnoliopsida Order: Lamiales Family: Lamiaceae Subfamily: Nepetoideae Tribe: Ocimeae Subtribe: Plectranthinae Genus: Coleus Species: Coleus rotundifolius