Haemadipsa picta Moore, 1929

Lai, Yi-Te, Nakano, Takafumi & Chen, Jiun-Hong, 2011, Three species of land leeches from Taiwan, Haemadipsa rjukjuana comb. n., a new record for Haemadipsa picta Moore, and an updated description of Tritetrabdella taiwana (Oka), ZooKeys 139, pp. 1-22 : 8-11

Haemadipsa picta Moore, 1929

Haemadipsa picta Moore, 1929.P. Acad. Nat. Sci. Philadelphia 81: 267-295.

Haemadipsa picta Moore, 1935. B. Raffles Mus. 10: 67-78.

Haemadipsa picta Keegan et al., 1968. Biomed. Rep. 406 Med. Lab. No. 16. United States Army Medical Commend, Japan.

Haemadipsa picta Ngamprasertwong et al. 2007.Nat. Hist. J. Chulalongkorn U. 7: 155-159.

Material examined.

L00099 collected at 18th Sept. 2005 in Hsoulin Town, Hualien County; L00100A collected at 12th Sept. 2004 in Hualien County; L00151A collected at 15th Oct. 2006 in Hsoulin Town, Hualien County; and L00152A collected at 31st Aug. 2003 in Hualien County.

Diagnosis.

This species can be recognized by the longitudinally striped color pattern on the reddish brown dorsum, with a broad, bluish-gray, yellow-greenish, or multicolored median-paramedian field that contains three to five black or dark brown broken stripes inside (Fig. 2A). It has a white or pale yellowish longitudinal marginal stripe with dark-spotted borders, as well as a uniformly yellowish brown venter, which distinguishes this species from other land leech species in Taiwan.

External morphology.

Body length 13-33 mm, maximum body width 3.0-5.5 mm, anterior sucker diameter 1.3-2.5 mm, posterior sucker diameter 2.5-3.7 mm. Body elongated, slenderly cylindrical, with dorsum moderately depressed from the end of body to the head; venter more or less flat in relaxed specimens. Head of dorsal anterior sucker with usual sub-triangular outline (Fig. 2B); venter of lip with the broad median field marked by narrow, longitudinal ridges and a deep median fissure. Anterior sucker deep, wide, triangularly cupuliform with well-developed lateral buccal lobes and frill. Posterior sucker nearly circular, slightly longer than wide, diameter equal to or a little larger than maximum body width, with a definite anterior median prominence but no sharply hooked papilla. Auricles large, white, trilobate with the middle lobe smallest, and conspicuous by their color in contrast with the body color.

Dorsum strongly tessellated, with areas bearing semi-transparent tipped sensillae in addition to the sensory annuli of each somite. Venter tessellated less and more smooth than dorsum. Dorsum of posterior sucker tessellated, with five or six irregular circles of polygonal areas. Venter of posterior sucker with rays 67 to 72, mostly 71, which in strongly flattened ridges terminating in little rounded lobes at the margin, and not penetrating into the central areolated region.

When alive, body color of reddish brown, or yellow brown in some specimens. Dorsum with three to five longitudinal, black or dark broken stripes of more or less partially and mutually connecting by dark spots in a broad, bluish gray, yel low -greenish, or multicolored median–paramedian field (Fig. 2A). In lateral body, white, pale yellowish, or dusty yellow–greenish marginal stripes bordered by a series of black spots submarginally and supramarginally, especially in half-posterior body. Venter uniform, yellowish brown or resembling color brighter than that in the dorsum, without any spots or stripes. Dorsum of posterior sucker yellow–greenish or yellowish brown, similar to the venter body. Venter of posterior sucker fawn, brighter than venter body.

Eyes five pairs, punctiform, arranging respectively at II (2nd annulus), III (3rd annulus), IV (4th annulus), V (6th annulus) and VI (9th annulus) in parabolic arc (Fig. 2B).

Ninety seven annuli. I, II and III uniannulate, with irregular areas divided and with sensillae in the interocular region. IV biannulate ((a1a2)>a3) and the interocular region being divided into irregular areas with sensillae in two transverse and sometimes oblique rows. V biannulate dorsally ((a1a2)>a3) and uniannulate ventrally, with the a3 as the oral margin of the buccal ring and also the first perfectly definite annulus. VI triannulate (a2>a1>a3). VII triannulate with the three annuli approximately equal. VIII quadrannulate (a1=a2>b5=b6). IX quinquannulate (a2>b1=b2=b5=b6). X–XXII midbody somite and quinquannulate, with the five annuli of the same length and a2 projecting slightly above the surface. XXIII quadrannulate (a2>a1= b5>b6). XXIV triannulate (b1=b2<a2), with b1 & b2 united at the margins and much reduced ventrally, and a2 bearing the first auricular lobe. XXV and XXVI uniannulate, each bearing the second and third auricular lobes at the margins. XXVII uniannulate. Anus in the furrow between XXVII (97th annulus) and the posterior sucker. Gonoporesseparated by five annuli; male at XI b5/b6 (31st/32nd annulus); female at XII b5/b6 (36th/37th annulus); both moderately large transverse slits strictly within furrows.

Internal morphology.

Jaws three, crescent-shaped, small and less prominent, with 78-80 teeth; one mid-dorsally, the other paired ones ventro-laterally, all in deep buccal chamber beyond the velum. Pharynx in VII–VIII, short, bulbous; with spongy muscular walls bearing many radiating fibers and surrounded by numerous unicellular salivary glands; extended into crop in IX. Crop in IX–XIX; with 11 pairs of caeca in each somite respectively; first 10 pairs simple and unlobed, while the tenth pair of caeca in XIX elongated posteriorly to XXIII and lateral to intestine. Intestine in XIX–XXIII, no caeca, with sharp sigmoid flexure and ventral to rectum in XXIII. Rectum short, sharply tapered towards anus.

Ten pairs of testisacs at XIII/ XIV–XXII /XXIII. Vas deferens enters epididymis in XIII. Epididymis in XII–XIII, massive, convoluted together, totally posterior to the atrium and covered on a small part of the cephalic end of the vaginal sac. Ejaculatory bulbs of moderate size and form, lying at a low level by the sides of the atrium, and connected by slender ejaculatory ducts to atrium in XI. Atrium large, conspicuous, rising well dorsad of the level of the nerve cord passing along in the left side. Prostate glands a layer of highly compact. Ovisacs in XII/XIII, on which with common oviduct long, sigmoid and slender. Vaginal stalk distinctly shorter than vaginal sac, which of an elongated egg-shape with the small apical end directed caudad in XIV–XVI (Fig. 2C).

Distribution.

This species is only recorded in South East Asia, including the Indo-Chinese Peninsula and Borneo. In Taiwan, it is a newly recorded species, and was collected in the moist forests of low- and middle-elevation mountains in Yilan, Hualien and Taitung during our recent surveys (Fig. 4).

Habitat.

Commonly found on bushes about 1 m above the ground in moist forests.

Host.

Primarily medium- or large-sized mammals, including humans.

Remarks.

Unlike many other land leech species which remain on the ground and grass below knee-level, this species usually climbs and waits on bushes and grasses at about 1 m above the ground, and attaches to the hands, arms, shoulders and even neck of passers-by ( Keegan et al. 1968). This species has been known to fall onto hikers from higher bushes or leaves (Chun-Chia Huang, pers. comm.). In comparison to other land leech species, the bites of this species are much more painful and difficult-to-heal; thus, Haemadipsa picta has been given the common name "stinging land leech" ( Moore 1929). Such painful and difficult-to-heal bites were also confirmed by a friend who collected specimens of Haemadipsa picta for us (Chun-Chia Huang, pers. comm.). However, this common name should be shared with another similar species, Haemadipsa ornata Moore, because it also has a similarly painful bite to Haemadipsa picta (Moore, 1929). Nevertheless, this common name is rarely used for Haemadipsa picta , while the name, "tiger leech", has been more commonly used, which refers to the colorful striped pattern (i.e., “picta” in the scientific name).