Multilocus systematics and non-punctuated evolution of Holarctic Myodini (Rodentia: Arvicolinae).

The tribe Myodini consists of five genera of forest and alpine voles (Alticola, Caryomys, Eothenomys, Hyperacrius and Myodes) distributed throughout the Holarctic. Because mitochondrial evidence has revealed paraphyly and polyphyly among genera, we apply the first multilocus tests to clarify taxonomy and phylogenetic relationships. Our analyses of 28 of 36 species within Myodini, including three not previously sequenced (A. montosa, A. albicaudus, and H. fertilis), identify four distinct clades and provide the first molecular evidence that Hyperacrius may not belong in Myodini. Myodes is paraphyletic, while polyphyly of Alticola reflects apparent ancient mitochondrial introgression. Diversification in this tribe was hypothesized to be tightly linked to Late Cenozoic climatic events, however, lineage through time analysis indicates diversification over the last 4 My was gradual and not strongly punctuated.

Coccidia (Apicomplexa: Eimeriidae) from the lagomorph Lepus tolai in Mongolia.

In 1999, a single specimen of the Tolai hare, Lepus tolai Pallas, 1778, from the Gobi region of Mongolia was examined and had a new species of eimerian parasite in its intestinal contents. Eimeria gobiensis n. sp. is relatively large; it possesses 2 oocyst walls and a very well-developed oocyst residuum. Oocysts of the new species possess a thick wall with a double layer, a massive 3-layered micropyle, and are ellipsoidal, with average length and width of the oocyst of 38.6 × 24.2 µm, respectively. The range in measurements of these oocysts extends from 27.3 to 49.2 µm in length by 18.8 to 32.5 µm in width, with a length/width ratio = 1.6; the oocyst residuumis is composed of a sub-spheroidal mass of small granules with an average size of 12.0 × 11.0 µm; sporocysts are ovoidal with an average length × width of 15.0 × 7.7 µm, respectively, and a range in length extending from 9.2 to 21.0 µm by 5.0 to 12.0 µm in width. In addition, each sporozoite has a large, medial, refractile body with an average size of 6.0 × 5.0 µm.

Mobile larynx in Mongolian gazelle: Retraction of the larynx during rutting barks in male Mongolian gazelle (Procapra gutturosa Pallas, 1777).

This study provides the first evidence of pronounced temporary laryngeal descent in a bovid species. An elaborate acoustic display is prominent in male courtship behavior of polygynous Mongolian gazelle. During rut, rounding up of females is accompanied by continuous head-up barking by dominant males. Throughout the rut their evolutionarily enlarged larynx descends to a low mid-neck resting position. In the course of each bark the larynx is additionally retracted toward the sternum by 30% of the resting vocal tract length. A geometric model of active larynx movements was constructed by combining results of video documentation, dissection, skeletonization, and behavioral observation. The considerable distance between resting position and maximal laryngeal descent suggests a backward tilting of the hyoid apparatus and an extension of the thyrohyoid connection during the retraction phase. Return to the resting position is effected by strap muscles and by the elastic recoil of the pharynx and the thyrohyoid connection. An intrapharyngeal inflation of the peculiar palatinal pharyngeal pouch of adult males is inferred from a short-time expansion of the ventral neck region rostral to the laryngeal prominence. The neck of adult dominant males is accentuated by long gray guard hairs during the rut. The passive swinging of the heavy larynx of adult males during locomotion gives the impression of a handicap imposed on rutting males. Apparently, this disadvantage becomes outweighed by the profits for reproductive success.

A new nematode, Soboliphyme ataahai sp. n. (Nematoda: Soboliphymidae) from Laxmann's shrew, Sorex caecutiens Laxmann, 1788 in Mongolia.

This report describes a new species of the soboliphymid nematode, Soboliphyme ataahai sp. n. from Laxmann's shrew, Sorex caecutiens. This species is distinguished from the previously known congeners by the notched cephalic sucker with a thin circumoral membrane, relatively long vagina, cephalic papillae arranged in clusters, and bursa possessing papillae on inner and outer surfaces. Also, Soboliphyme ataahai differs from the congeners in other characters, such as position of vulva, number and distribution of cervical sacs, structure of cephalic sucker, body size, and dimensions of organs.