Carinartemis exacutus (Gould, 1856)

Sian Man, Nem, Siriboon, Thanit, Lin, Aung, Sutcharit, Chirasak & Panha, Somsak, 2022, Revision of the carnivorous land snail family Streptaxidae (Stylommatophora, Achatinina) in Myanmar, with description of four new species, ZooKeys 1110, pp. 39-102 : 39

publication ID

https://dx.doi.org/10.3897/zookeys.1110.85399

publication LSID

lsid:zoobank.org:pub:4681CC6D-E5F3-47C6-B1D0-52DEA78BE7C3

persistent identifier

https://treatment.plazi.org/id/202F0534-1A86-581E-B898-8C1AD67FD947

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scientific name

Carinartemis exacutus (Gould, 1856)
status

 

Carinartemis exacutus (Gould, 1856)

Figs 1 View Figure 1 , 2D View Figure 2 , 17C, D View Figure 17 , 18 View Figure 18 , 21A, B View Figure 21 , 22 View Figure 22 , 24D View Figure 24

Streptaxis exacutus Gould, 1856: 13. Type locality: Burma [Myanmar].

Streptaxis exacuta [sic] - Pfeiffer 1859: 331.

Streptaxis exacutus - Pfeiffer 1871: 30, 31, pl. 115, figs 13, 14. Hanley and Theobald 1870: 40, pl. 98, figs 8-10. Nevill 1878: 3. Tryon 1885: 72, pl. 14, figs 11, 12. Blandford and Godwin-Austin 1908: 8.

Haploptychius exacutus - Kobelt 1906: 142, 143, pl. 57, figs 16-18. Richardson 1988: 215. Siriboon et al. 2014b: 169, 171.

Material examined.

Moulmein: NHMUK 1874.9.3.15 (3 shells) ex. Godwin-Austen. NHMUK 1888.12.4.771-773 (3 shells; Fig. 17C View Figure 17 ). NHMUK 1906.2.2.198 (3 shells + 2 juveniles; Fig. 18A View Figure 18 ) ex. Blanford collection. NHMUK 1903.7.1.3999 (3 shells) ex. Godwin-Austen collection. Burma: NHMUK1950.12.9.170 (1 shell) ex. Laidlaw collection. Mergui : NHMUK ex. Cuming collection (2 shells). Sadhdan Cave , Hpa-an Township , Hpa-an District , Kayin State, Myanmar (16°44'23.4"N, 97°43'04.2"E): CUMZ 13020 (3 shells). Bayin Nyi Cave , Hpa-an Township , Hpa-an District , Kayin State, Myanmar (16°58'10.1"N, 97°29'30.6"E): CUMZ 13021 (8 shells; Fig. 18B View Figure 18 ), CUMZ 13022 (15 specimens in ethanol). Lun Nga Mountain , Hpa-an Township , Hpa-an District , Kayin State, Myanmar (16°44'53.2"N, 97°47'09.5"E): CUMZ 13023 (14 shells; Fig. 18C View Figure 18 ), CUMZ 13024 (50 specimens in ethanol). Taung Wine Cave , near Thiri Hpa-an Hotel, Hpa-an Township , Hpa-an District , Kayin State, Myanmar (16°50'31.1"N, 97°37'18.4"E): CUMZ 13025 (3 shells; Fig. 17D View Figure 17 ), CUMZ13026 (6 specimens in ethanol). Kaw Ka Taung Cave ( Golden valley ), Hpa-an Township, Hpa-an District, Kayin State, Myanmar (16°50'32.4"N, 97°37'10.9"E): CUMZ 13027 (1 shell) GoogleMaps .

Diagnosis.

Carinartemis exacutus is superficially similar to C. sankeyi , C. vesperus Siriboon & Panha, 2014, and C. striatus Siriboon & Panha, 2014 from western Thailand, but it has a larger shell, convex spire, immediately expanded penultimate whorl, semi-ovate aperture, two parietal lamellae, very thickened penial sheath, vas deferens passes through penial sheath, curved portion of vas deferens with very thin connective tissue, and hooks located on irregular trapezoidal penial papillae separated by longitudinal folds. In comparison, C. sankeyi , C. vesperus , and C. striatus have an elevated spire, regularly expanded penultimate whorl, but C. sankeyi has fine transverse ridges on the entire shell, subquadrangular aperture, one parietal lamella, slender atrium, thin penial sheath, vas deferens does not pass through a penial sheath, curved portion of vas deferens is without connective tissue, proximal penial hook located on laterally-flattened penial papillae, and distal penial hooks located on laterally compressed penial papillae separated by reticulated folds. In contrast, C. vesperus has a subcircular aperture, lacks parietal lamellae, has a less axially deflected last whorl, vas deferens passes through the penial sheath, curved portion of vas deferens is without connective tissue, and penial papillae absent. Meanwhile, C. striatus has strong transverse ridges over the entire shell, a semi-ovate aperture, one parietal lamella, vas deferens is attached to the distal end of the penial sheath with very thin connective tissue, and hooks are located on papillae without connected longitudinal folds.

Description.

Shell oblique-heliciform, white, and translucent; whorls 6- 6½; spire convex with distinct suture. Shell surface glossy with fine transverse ridges, nearly smooth with few transverse ridges near peristome; varices present. Embryonic shell ~ 2½ whorls with smooth surface; following whorls intermediately coiled. Shell periphery wide and sharply keeled along nearly the entire penultimate whorl; last whorl axially deflected. Aperture semi-ovate; peristome discontinuous, thickened, expanded, and slightly reflected. Apertural dentition with one strong parietal lamella and sometimes with a second parietal lamella adjoined at a right angle. Umbilicus open and deep (Figs 17C, D View Figure 17 , 18 View Figure 18 ).

Genital organs. Atrium (at) short. Penis (p) a very thin, and long tube. Penial sheath (ps) muscularly enlarged, very thickened and extending entire length of penis; penial sheath retractor muscle (psr) thin, originating near genital orifice, attached to atrium with short and thin connective tissue, and inserting distally on penial sheath (Fig. 21A View Figure 21 ). Vas deferens (vd) passes through a short portion of penial sheath, then extends to curved portion at ~ 1/11 of the penial sheath length before entering penis distally. Curved portion of vas deferens with very thin connective tissue originating at penial sheath (Fig. 21B View Figure 21 ). Penial retractor muscle (pr) thin, very long, inserting at penis and vas deferens junction.

Internal wall of atrium generally smooth with sparse atrial pores (Fig. 22A View Figure 22 ). Penial wall with scattered pale brownish penial hooks, ~ 20 hooks/200 μm 2; hooks located on laterally flattened penial papillae and separated by longitudinal folds (Fig. 22B-D View Figure 22 ). Penial hooks small (<0.02 mm in length), expanded at base, tips pointed and curved towards genital orifice (Fig. 22E, F View Figure 22 ).

Vagina (v) very short and ~ 1/12 of penis length. Gametolytic duct (gd) a long tube extending as far as albumin gland; gametolytic sac (gs) ovate. Proximal free oviduct (fo) enlarged then tapering to smaller diameter distally. Oviduct (ov) enlarged and folded; prostate gland inconspicuous and bound to oviduct. Talon (ta) small, short and club shaped. Hermaphroditic duct (hd) bearing long seminal vesicle (sv) ~ 1/2 the length from talon to branching point of seminal vesicle (Fig. 21A View Figure 21 ).

Vaginal wall with longitudinal oblique vaginal folds, folds with nearly smooth surface and vaginal hook absent (Fig. 22G View Figure 22 ).

Radula . Each row consists of 41-45 teeth with formula (22-20)-1-(20-22). Central tooth is very small with pointed cusp. Lateral and marginal teeth undifferentiated, lanceolate, unicuspid, and lanceolate. Latero-marginal teeth gradually reduced in size, with outermost teeth much smaller and shorter than inner teeth (Fig. 24D View Figure 24 ).

Distribution.

This species was collected from five limestone hills in Kayin State, southern Myanmar, in this survey.

Remarks.

This species appears at a high abundance among the limestone karsts in Hpa-an, Kayin State. All the specimens examined from the populations from Lun Nga Mountain and Bayin Nyi Cave have a very small to indistinct upper parietal lamella, and some specimens from Bayin Nyi Cave have strong transverse ridges on almost the entire whorl. Moreover, the Lun Nga Mountain population have a last whorl that is more extended anteriorly and an elongated semi-ovate aperture (Fig. 18C View Figure 18 ). However, the genitalia in all localities show no difference from this locality; thus, we consider them as intraspecific variations within C. exacutus . Some specimens from Bayin Nyi Cave have strong transverse ridges on almost the entire whorl.

Although the type locality was listed as ‘Burma’ [Myanmar], all the known records and specimens examined in this study were collected from Kayin State. Therefore, the precise type locality of this species is probably southwestern Myanmar in Mon State and Kayin State.

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

Order

Stylommatophora

Family

Streptaxidae

Genus

Carinartemis

Loc

Carinartemis exacutus (Gould, 1856)

Sian Man, Nem, Siriboon, Thanit, Lin, Aung, Sutcharit, Chirasak & Panha, Somsak 2022
2022
Loc

Streptaxis exacutus

Gould 1856
1856
Loc

Streptaxis exacutus

Gould 1856
1856