Higher-level relationships of snakes inferred from four nuclear and mitochondrial genes

Higher-level snake relationships are inferred from sequence analyses of one nuclear gene (C-mos) and three mitochondrial genes (12S rRNA, 16S rRNA and cytochrome b). Extant snakes belong to two lineages: the fossorial Scolecophidia, which feed on small prey on a frequent basis, and the ecologically diverse Alethinophidia ('typical' snakes), which feed on large prey on an infrequent basis. The vast majority of Alethinophidia, if not all of them, belong to two clades, corresponding to two distinct prey neutralization modes: unimodal constriction for the Henophidia (locomotor and feeding systems coupled) and injection of toxic saliva, in addition (or not) to diverse alternate modes of constriction, for the Caenophidia (locomotor and feeding systems uncoupled). Within Alethinophidia, non-macrostomatan (small gape) Aniliidae (genus Anilius) and macrostomatan (large gape) Tropidophiidae (genera Trachyboa and Tropidophis), both from the Neotropics, are closest relatives. Although our data are insufficient to robustly infer the ancestral mode of life of snakes, we find evidence of plasticity in the basic ecological and trophic modes of snakes. Consequently, the macrostomatan condition should not be treated a priori as a derived character state devoid of homoplasy.     

Bifurcations in a white-blood-cell production model

We study the dynamics of a model of white-blood-cell (WBC) production. The model consists of two compartmental differential equations with two discrete delays. We show that from normal to pathological parameter values, the system undergoes supercritical Hopf bifurcations and saddle-node bifurcations of limit cycles. We characterize the steady states of the system and perform a bifurcation analysis. Our results indicate that an increase in apoptosis rate of either hematopoietic stem cells or WBC precursors induces a Hopf bifurcation and an oscillatory regime takes place. These oscillations are seen in some hematological diseases.     

Two new species of seahorses (Syngnathidae, Hippocampus) from the Middle Miocene (Sarmatian) Coprolitic Horizon in Tunjice Hills, Slovenia: The oldest fossil record of seahorses

Two new and the only known extinct seahorse species Hippocampus sarmaticus and Hippocampus slovenicus are described from the Middle Miocene beds (Lower Sarmatian) in Slovenia, representing the oldest known fossil record of seahorses. Hippocampus sarmaticus was most similar to the extant seahorse species Hippocampus trimaculatus, while H. slovenicus can be most easily compared to the extant pygmy seahorses H. bargibanti, H. denise, and H. colemani. These Sarmatian seahorses lived among seagrasses and macroalgae in the temperate shallow costal waters of the western part of the Central Paratethys Sea.     

太行山前平原麦田昆虫种类调查及4种药剂对麦红吸浆虫的药效实验

以藁城为例,采用淘土、扫网、挂黄板等方法对太行山前平原麦田昆虫群落进行了调查,结果表明该区域超高产麦田昆虫种类相对较少,总计22种,隶属于6目14科。害虫主要有2类,吸浆虫类和麦蚜类。小麦吸浆虫以麦红吸浆虫为主。天敌昆虫常见有蚜茧蜂、食蚜蝇、草蛉和瓢虫4类。采用氧乐果、毒死蜱、高效氯氰菊酯、吡虫啉4种常用药剂对麦红吸浆虫成虫进行了田间药效实验,结果表明上述4种药剂对麦红吸浆虫均有较好的防治效果,虫口减退率均在80%以上。其虫口减退率从高到低依次为:氧乐果、毒死蜱、高效氯氰菊酯、吡虫啉。建议根据麦红吸浆虫的发生情况,选择中低毒药剂毒死蜱、高效氯氰菊酯、吡虫啉交替使用。     

Further support for the clades obtained by multiple molecular phylogenies in the acanthomorph bush

Several recent molecular studies have begun to clarify the phylogeny of Acanthomorpha (Teleostei), a wide clade of teleost fishes. However, different molecular datasets do not agree on a single history of the taxa, probably because of marker-specific biases. The 'total-evidence' approach maximizes character congruence, but may be biased by a single robust, but non-phylogenetic constraint from one dataset. We have therefore taken the approach to analyse also each dataset separately prior to their combination, and detect repeated groups: signal common to markers is more probably a reflection of shared ancestry than marker-specific signal. Partial sequences (678+527 base pairs) of exons of the MLL gene (Mixed Lineage Leukaemia-like) gene were used, as well as the datasets of Chen et al. (ribosomal 28S, rhodopsin gene, mitochondrial 12S and 16S). Most of the repeated clades of Chen et al. are supported by the new dataset. Some new groups were repeatedly found: a Scarus-Labrus group (clade M), the presence of Gasterosteidae as a sister taxon or within the clade Zoarcoidei-Cottoidei (clade Is), Polymixia as a sister-group to the clade Zeoidei-Gadiformes (clade O), the clade Q grouping Mugiloidei, Cichlidae, Atherinomorpha, Blennioidei and Gobiesocoidei; and the interesting clade N, reducing potential sister-groups to Tetraodontiformes to either Caproidei, Lophiiformes, Acanthuroidei, Drepanidae, Chaetodontidae, and Pomacanthidae.     

不同产地南方红豆杉各家系幼苗生长、光合生理与株高生长节律的差异分析

为充分了解不同产地南方红豆杉也Taxus wallichiana var. mairei ( Lemée et H. Lév.) L. K. Fu et Nan Li页各家系幼苗生长、光合生理及株高生长节律的差异,以产自江西分宜( FY)、浙江龙泉( LQ)、福建建瓯( JO)和福建明溪( MX)的20个家系的2年生容器苗为研究对象,对幼苗的株高和地径以及叶片的净光合速率和叶绿素含量进行比较,并对各家系的株高生长进行Logistic拟合回归分析以及拟合曲线参数和株高生长节律参数的计算和分析;在此基础上,分析了不同指标间的相关性并对供试的20个家系进行聚类分析。结果显示：不同产地间南方红豆杉的株高、地径、叶绿素含量和净光合速率均无显著差异,但这些指标在不同家系间均有极显著差异(P<0.01);各家系的株高、地径、净光合速率( Pn)以及叶绿素a( Chla)、叶绿素b( Chlb)和总叶绿素( Chl)含量的最大值较最小值分别高52.99%、29.63%、115.65%、39.81%、30.95%和37.24%。4个产地的株高生长均呈明显的“S型”曲线;各家系的最大生长速率( MGR)、线性生长速率( LGR)、线性生长总量( TLG)和线性生长持续时间( LGD)的最大值较最小值分别高60.00%、61.54%、63.73%和22.73%;从线性生长始期(t1)和线性生长终期(t2)来看,各家系的速生期为5月中旬或下旬至8月上旬。幼苗的株高与MGR、TLG、LGR、地径、Pn、Chlb和Chl等指标均极显著正相关,并与Chla显著正相关,而地径与MGR、TLG、LGR、Pn和Chlb等指标显著正相关,但株高和地径与LGD均无显著相关性。聚类分析结果表明：在欧氏距离10处,供试的20个家系被分成4个类型,其中,第Ⅳ类的6个家系的幼苗生长最佳且生长潜力最高。研究结果表明：不同产地南方红豆杉各家系的遗传变异丰富,且株高和地径生长主要受生长速率的影响;总体来看,家系LQ09、LQ11、FY21、FY26、MX12和MX18的幼苗生长潜力较高,可作为南方红豆杉的优良家系进行推广。     

The first juvenile specimen of Eolacerta (Squamata: Eolacertidae) from the early–middle Eocene of the Messel Pit (Germany)

We describe the first juvenile specimen of an eolacertid lizard. The material comes from one of the most important Eocene localities, the Messel Pit in Germany. The new specimen provides unique information on the early ontogeny of Eolacerta, the largest known lizard from Messel, with a maximum snout-vent length greater than 30 cm and a mass approaching 1 kg. The specimen described here, with a SVL of 11.3 cm and an estimated mass of 21 g, can be allocated more precisely to Eolacerta robusta based on the co-occurrence and the combination of following features: (1) the nasal process of premaxilla is long; (2) position of lacrimal (being more anteriorly located in Stefanikia siderea); (3) the postorbital process of jugal is broad; (4) the ratio of the anterior and posterior region of the frontal between the sulcus interfacialis; (5) a mid-parietal constriction of the parietal table is present; (6) the interparietal shield broadens anteriorly; (7) the transverse sulcus is straight anteriorly. The incipient character of the parietal constriction and the slightly lower number of maxillary teeth (28 vs. 30–32 in adults) are consistent with a juvenile animal. Very important is evidence for the presence of pterygoid dentition (pointed teeth arranged in a single line) and the absence of palatine dentition. Ceratobranchial I is observed for the first time for this species, and its shape and length are very similar to those of Lacertidae. There are 27 presacral vertebrae in the juvenile, as in adults. In the juvenile specimen, ventral keel on the centrum is present in all vertebrae. The ventromedial portion of the ischium is well preserved here and gives information on the exact shape of this portion, at least in juvenile form. The scalation, as far as it is preserved, is similar to that of Stefanikia, except that the rectangular subdigital scales are longer in comparison with their width, and therefore have a broader appearance.     

棉田玉米螟的田间发生为害观察

灯下所诱玉米螟Ostriniafurnacalis（Güenée）雌蛾,二、三代分别为76．05％及59．91％,蛾峰后4～5天出现卵峰。主茎叶及棉株下部的卵量随产卵时间的推移,逐渐递减,而趋向棉株上部及外围。二代卵以下部2～3层为多,三代卵以2～4层果枝为多,内围多于外围;93％以上的卵产于绿叶反面;棉田卵寄生的高低与施药有关,且明显低于玉米田;二代5～10层蛀茎占总数的84．44％,三代4～8层蛀铃占59．79％。卵密度不同,蛀铃分布也不同。     

Pollen Tetrads in Lilium with a Discussion on the Delimitation Between L.semer vivoideum and Its Ally

In the course of our palynological study on the Chinese Lilium, pollen tetrads are found in two taxa of the genus: L. sempervivoideum and L. amoenum. The latter is distributed in NW. and S. Yunnan Province. It was established by Wilson, but reduced later by himself to a synonym of L. sempervivoideum which occurs from S. Sichuan to C. Yunnan. However, it is regarded as a species distinct from the former by many authors, such as Sealy (1949), Woodcock and Stearn (1950) and S. Y. Liang (1980). Their pollen tetrads are similar in aperture appearance and sexine patterns, but different in the shape, size and arrangement of sculptural elements, as shown by LM and SEM examination. Their leaf shape and flower colour are different, though there are some transitions between them. Based on the facts mentioned above, it is reasonable to regard the two taxa as two subspecies in L. sempervivoideum.     

Les vertébrés dévoniens de l'Iran central: IV: Arthrodires et ptyctodontes

The Upper Devonian localities of the Kerman and Tabas area yielded numerous brachythoracid arthrodire remains, referred here mainly to Golshanichthys asiatica nov. gen., nov. sp., and Holonema cf. radiatumObrouchev. Some specimens are suggestive of species belonging to the genera Plourdosteus, Eastmanosteus and Aspidichthys. G. asiatica is a primitive dinichthyid characterized by e.g. very deep posterior and anterior embayments of the central plates.Some ptyctodontid tooth plates of «Rhynchodus and «Ptyctodus type have been found in the Frasnian and Famennian.