Relationship Between Species Diversity And Environment In China

Tardigrades are the invertebrates with the tiny body. They distribute around the world with the features of anhydrobiosis, cryobiosis, osmobiosis, and anoxybiosis and are able to be exposed to in the ultrahigh pressure and ultraviolet radiation, which are of great research value.This paper targets at the research of tardigrades in China, adopting the quadrat method to research the wild communities of tardigrades, which covers the areas of Wuyi Mountaions, Jinggang Mountains, Nanling, Shen Nongjia, Taihang Mountains, Lvliang Mountains, Great Khingan Mountains, Lesser Khingan Mountains and Changbai Mountains. The first step is to collect specimen and make the separation and identification in laboratory, then sum up the formation of tardigrades in every community. Meanwhile, the ecological and statistical methods are used to do the data process so as to explore the features of the diversity of tardigrades and its changing rules and seek its relation with the environmental factors, considering the annual average precipitation and temperature in the collection sites.The research mainly includes the fauna in different areas, which determines the features of tardigrades in every community and the changes of composition of different communities so as to calculate the diversity index of tardigrades and analyse the mutual relationship betweem the diversity index, precipitation and temperature.The research results of the relationship between the diversity of tardigrades in China and environment are as following:China is rich in the tardigrades species. The initial statistics includes2orders,3families,6subfamilies,20genera,177species including5new species(Echiniscus crebraclava, Hypechiniscus fengi, Diphascon gani, Doryphoribius mcinnesae, Macrobiotus wuyishanensis)、2newly recorded genera (Hypechiniscus、Calohypsibius) and21newly recorded species(Echiniscus bigranulatus、Echiniscus curiosus、 Echiniscus dreyfusi、Echiniscus menizdi、Echiniscus perarmatus、Echiniscus phocae、 Echiniscoides pooensis、Echiniscus scrabrospinesus、Echiniscus semifoveolatus、 Echiniscoides sigismundi、Isohypsibius stenostomus、Diphascon(Diphascon) nobilei、 Diphascon(Diphascon) sexbullatum、calohypsibius ornatus、Calcarobiotus (Calcarobiotus) digeronimoi、Macrobiotus crenulatus、Macrobiotus hibiscus、 Macrobiotus ragonesei、Macrobiotus tericola、Minibiotus scopulus、Ramazzottius anonalus).Hypechiniscus fengi:Small in size. Colorless or very light yellow. Eyespots almost invisible. Sculpture composed of numerous very fine pits, which cover plates and cuticle between them. Ventral side smooth. Cephalic appendages include internal buccal cirrus, cephalic papilla, external buccal cirrus, cirrus A, and clava. Both primary clava and secondary clava papilla-like. Cirrus A with large basis. Robust median dorsal spine arising from anterior margin of second paired plate,median dorsal spine extends to anterior margin of third median plate; Dd present. Armor consists of single cephalic plate, small neck plate, scapular plate, first single median plate, first paired-plates, second median plate, second paired-plates, third median plate, and terminal plate; suture of large head plate nearly separates plate into five pieces; second median plate much larger than first and third median plates; median longitudinal ridge extends in antero-posterior direction, which nearly divides second and third median plates into two parts; terminal plate with normal notches; lateral intersegmental plates present between segmental plates and median plates1,2and3. However, dorsal plates sometimes indistinct. Leg plate, dentate collar, and papilla absent on all legs. Robust spurs point toward base of claw present on internal two claws on all legs; small but distinct sharp spur usually present at base of external claws on hind legs. The new species differs from Hypechiniscus exarmatus in having a robust median dorsal spine and in having larger spurs on the internal claws.The new species differs from H. gladiator in lacking a dentate collar on the fourth pair of legs. Finally, this new species differs from H. papillifer in lacking any papillae on all four pairs of legs.Echiniscus crebraclava:Body brown. Eyespots absent. Cuticular sculpture composed of densely distributed pores with six projections along the edge of each pore; the pores on the cephalic plate smaller than on other plates, larger pores present on the terminal and the second median plates. A necklace with pendant like suture present on the dorsal side of the cephalic plate. Cephalic appendages include internal buccal cirrus, cephalic papilla, external buccal cirrus, cirrus A, and clava. Clava curved and very thick. Armor consists of single cephalic plate, small neck plate, scapular plate, first single median plate, first paired-plates, second median plate, second paired-plates, and terminal plate. A spine present on the external side of the first pair of legs. Dentate collar with7teeth present on the hind legs. A papilla present on the external side of the hind legs. Claws greatly curved; weak spurs present near the base of the internal claws on all legs.Diphascon (Adropion) gani:Body colorless. Eyespots present. Cuticle smooth. Bucco-pharyngeal apparatus of the Diphascon type. Drop-shaped cuticular thickening between the buccal tube and the pharyngeal tube absent; bucco-pharyngeal tube long and narrow. Six peribuccal lobes present. Pharyngeal apophyses well-developed; pharyngeal bulb round sherical with two macroplacoids, the first one rodshaped with a constriction, the second one elliptical and much shorter than the first one; microplacoid absent, septulum present. Claws of the Hypsibius type. Accessory points present. Lunules absent. Cuticular bar near the claws absent on all legs.Macrobiotus Wuyishanensis: Colorless. Eyespots present. Cuticle smooth without pores, dots or any other sculptures. Bucco-pharyngeal apparatus of Macrobiotus-type. Mouth terminal with10peribuccal lamellae. Oral cavity armature well developed and composed of a band of teeth in shape of a row of small ridges parallel to the main axis of the buccal tube and3ventral transverse ridges. Buccal tube with the ventral lamina and one bend in anterior part of tube. Pharyngeal bulb spherical with apophyses, two macroplacoids and a microplacoid. Pharyngeal apophyses obvious upset triangle-shaped. First macroplacoid rod-shaped with a medial projection that points inward becomes narrower in anterior part, much longer than the second macroplacoid, the second macroplacoid rod-shaped, slightly curved, a slight constriction at the proximal end. Microplacoid medium, thin and placed close to the second macroplacoid. Claws of hufelandi-type. Claws with an evident thin stalk, external claws larger than internal claws; the primary branch longer than the secondary branch; primary branches in all claws on all legs with strong accessory points. Lunules smooth on all legs. Egg laid free, spherical, without areolation. Projections cone-shaped, surface of the projection smooth without any sculpture, shell surface between the conical projections smooth。Echiniscus semifoveolatus、A newly recorded species. Small in size. Black eyes present. Body colour brown. Cuticular sculpture composed of irregular polygon-shaped depressions; most are pentagon-or hexagon-shaped, a few approximately rounded. The depressions on the scapular and terminal plates are much larger than those on the other dorsal plates including the cephalic plate. The dorsal plates consist of the cephalic plate, scapular plate, first median plate, first paired plates, second median plate, second paired plates, third median plate and the terminal plate. The cephalic appendages consist of the internal buccal cirrus, cephalic papilla, external buccal cirrus, cirrus A, and the clava. The lateral appendages include cirrus C, cirrus D, and cirrus E; cirrus B unilateral, tiny, and present only in one specimen. All lateral cirri very robust. The dorsal appendages include, not only the traditional dorsal spines of some Echiniscus species Bd, Cd and Dd, but also spines that arise from the posterior margin of the scapular plate (spines Bmd)(when present, up to five), a pair of spines present at the posterior margin near the central suture of the first paired plates (Cmd) and the second paired plates (Dmd). Ventral side of the body smooth without any plate or sculpture. A spur present on the external side of the first pair of legs. A papilla present on the external side of the hind legs. Dentate collar present on the hind legs with9teeth. Spurs that pointed towards the base of the claw present on the internal claws on all legs.The influencing factors are not considered in the description of communities, in which Margale index (R) is the optimal index, however, Shannon-wiener index (H) is the optimal index when considering the temperature and Pielou index (J) is the optimal index when considering precipitation. The constitution of dominant species in different communities is different and the frequency of all kinds of dominant species in the same community is also different. The same dominant species take on different frequency in different communities. There is obvious difference in the adaption to the temperature and humidity. There are also differences in diversity index influenced by temperature and precipitation:0.01<H=O.020.05(for temperature). There is the obvious difference in H.0.01<J=0.05=0.05(for precipitation). There is the obvious difference in Pielou index (J). The matching of diversity index E and annual average temperature is E=0.82-0.01T (P<0.05). The matching of diversity index R and annual average precipitation is R=0.083.