Dina punctata punctata Johansson, 1927

Ahmed, Raja Ben, Bielecki, Aleksander, Cichocka, Joanna M., Tekaya, Saïda, Gorzel, Małgorzata & Harrath, Abdul Halim, 2013, Erpobdellid leeches (Annelida, Clitellata, Hirudinida) from Tunisia: New records with the description of a new Trocheta species, Zootaxa 3681 (4), pp. 440-454 : 443-444

Dina punctata punctata Johansson, 1927

Material examined. 137 specimens collected in: Aïn Amdoun, Béja (36°46'216“ N, 09°56’821” E), Aïn Touta (36°88’403“ N, 09°53’513” E), Aïn Sidi Rhouma (36°17’575” N, 08°87’473” E), Aïn Oued Ramil, Kef (36°11’539” N, 08°63’863” E), Aïn Soltane, Siliana (35°48’424” N, 09°21’588” E), Aïn Tfifila (35°51’215” N, 09°43’385” E), Aïn Essaniya, Siliana (35° 46’141”N, 09°26’450” E), Aïn Zakkar, Siliana (36°01’298” N, 09°32’181” E), Aïn Serkha, Fernana (36°62’593” N, 08°71’408” E), Aïn Zoulèl, Bullarijia (36°56’531” N, 08°78’953” E), Aïn Sidi Saleh, Bizerte (37° 12' 302'' N, 10° 04' 0 0 2 ”E).

Description of examined specimens. The length of preserved leeches ranges from 38 to 45 mm; the width of the mid-body region is 3–5 mm. Both anterior and posterior suckers are transversally elliptical. The colour of living specimens is brown to green. The dorsal surface is covered by yellow spots that are arranged transversally on annulus a2, with rough surface due to the presence of small papillae ( Fig. 3 c). On the dorsal side is a pair of faded paramedian stripes. The ventral surface is grayish in colour ( Fig. 3 d). The somites are divided to four short annuli and an elongated one ( Fig. 6 b). Head with four pairs of eyes. The gonopores are separated by two annuli, with prominent male gonopore.

The male reproductive system consists of numerous and globular testes that form voluminous, grape-like structures of testisacs situated latero-ventrally. The sperm duct has a length of 7 ns, reaching the XX ganglion. The ejaculatory duct forms a preatrial loop. The relatively narrow atrium is 0.7 ns in length. Cornua are slightly expanded, bending to the ventral side. They are sharply coiled to connect with the ejaculatory ducts. The bursa is relatively big and enlarged ( Fig. 4 .d, e, f). The ovisacs are paired convoluted organs lying mid-ventrally; they start at ¼ part of the distance between the ganglia XII and XIII, and ends at the ganglia XVI.

Ecology and distribution. Dina punctata punctata is the most commonly observed leech occurring in almost the entire examined territory (north of Tunisia). It has only been recorded in small brooks and stagnant, often temporal water bodies connected to springs in mid to high elevations (265–1010 m). They are semi-aquatic annelids. As they are absent in the dry season, we suppose that these speimens bury deep into the soil during this period. They appear again in the winter to reproduce.

Figures

FIGURE 3. Photos of live erpobdellid specimens.; a – b: E. testacea; c – d: D. punctata punctata; e – f: D. punctata maroccana; g – h: T. africana; D. F—dorsal view (this aspect looks brighter than the ventral one because of the uneven illumination conditions); V. F—ventral view; Scale bar: 0.6 cm.

FIGURE 4. Ventral, dorsal and lateral views of male atria of mature specimens: a – c: E. testacea; d – f: D. punctata punctata; g – i: D. punctata maroccana; j – l: T. africana; m – o: T. tunisiana n. sp.

FIGURE 6. a: Reproductive system of T. tunisiana n. sp.: atrium (at), ovisacs (o), preatrial loops (pr. l), sperm ducts (s), testisacs (t); b: anterior sucker of T. africana in the left (after Nesemann and Neubert, 1994) and T. tunisiana n. sp. in the right; arrows point to the pseudognathes; c: Schematic annulations type and gonopores of both Tunisian species of Trocheta.