Ecomorphological diversification among South American spiny rats (Rodentia; Echimyidae): a phylogenetic and chronological approach

The phylogeny of South American spiny rats (Rodentia; Echimyidae) was studied using the exon 28 of the von Willebrand Factor nuclear gene (vWF). Sequences were analysed separately and in combination with a mitochondrial dataset (cyt b, 12S and 16S rRNAs) used in previous publications. The basal polytomy of echimyids was partially resolved and unexpected intergeneric clades were recovered. Thus, the intimate nested position of Myocastor within echimyids is evidenced. A well-supported clade is identified, including all the arboreal genera, and a group formed by Myocastor, Thrichomys, and Proechimys+Hoplomys. The clustering of Euryzygomatomys+Clyomys with Trinomys is also suggested. On the opposite, the phylogenetic position of Capromys as well as the relationships among arboreal genera remain unclear. Molecular divergence times were estimated using a Bayesian relaxed molecular clock and suggest a Middle Miocene origin for most of modern genera. The ecomorphological diversification of echimyids is discussed in the light of these new results and past environmental modifications in South America.     

Systematic position and phylogenetic relationships of the family Omphalometridae (Digenea, Plagiorchiida) inferred from partial lsrDNA sequences

The phylogenetic relationships and systematic position of the digenean genus Omphalometra Looss, 1899 and several other closely related genera, have always been controversial and opinions of different authors on the systematic rank and content of this group have varied greatly. Molecular analysis based on the partial sequences of the large subunit ribosomal DNA gene of representatives of the genera Omphalometra, Rubenstrema and Neoglyphe as well as previously published sequences of members of five families of Plagiorchioidea, has demonstrated: (1) close phylogenetic relationships between these three genera, and (2) a strong support of their position within the family Plagiorchiidae as a well-defined separate clade considered here as a subfamily Omphalometrinae. Molecular data do not support the close affinities of the members of Omphalometrinae and genus Opisthioglyphe as has been suggested by majority of previous authors. Among Omphalometrinae, Omphalometra flexuosa (a parasite of moles, Talpidae) occupies a basal position in relation to Rubenstrema exasperatum and Neoglyphe locellus (both parasitic in shrews, members of the more evolutionary advanced family Soricidae). An extremely low level of lsrDNA sequence divergence between Neoglyphe and Rubenstrema suggests very close phylogenetic relationships of these two genera. Results of the molecular analysis are briefly discussed in comparison with the previously published systems.     

Phylogeny and biogeographical history of Trogoniformes, a pantropical bird order

With highly conserved morphology throughout the family, a tropical distribution, and no close living relatives, the trogons (Aves: Trogonidae) pose a difficult problem for systematists. Disjunct tropical distributions are often attributed to Gondwanan vicariance, but the fossil record for trogons is mostly from the Tertiary of Europe. This study examined support for the basal relationships among trogons using a combination of nuclear (RAG-1) and mitochondrial (ND2) DNA sequence data. Although some nodes could not be resolved with significant support, there is strong support for the basal position of three New World genera ( Pharomachrus , Euptilotis , and Priotelus ). This phylogenetic hypothesis differs markedly from previous studies of trogon relationships and taxonomic treatments. Biogeographically, it implies an origin and early vicariance events for the crown clade in the New World. Molecular divergence estimates place all of the basal nodes of the trogon phylogeny in the Oligocene, precluding a Gondwanan origin for modern trogons.  © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 84 , 725–738.     

基于COⅡ基因序列的斑腿蝗科部分亚科的分子系统学研究

采用PCR产物直接测序法测定了斑腿蝗科10个亚科16属22种的COⅡ基因585 bp的片段, 对序列的碱基组成进行了分析,并评估了数据集的系统发育信号;最后,以癞蝗科的肃南 短鼻蝗作为外群,采用NJ法、MP法、ML法以及贝叶斯推论法构建了系统树,以解决这些物种所代表的亚科之间的系统发育关系。结果表明：22种斑腿蝗科昆虫的COⅡ基因序列碱基组成表现强烈的A+T含量偏向性。对COⅡ基因585 bp序列片段构成的全数据组和根据密码子不同位点划分的密码子第一、第二和第三位点数据组的系统发育信号分析显示,所有数据组都具有一定的系统发育信息。在4种方法得到的合一树中发现： （1）星翅蝗亚科、刺胸蝗亚科、黑背蝗亚科、斑腿蝗亚科的亲缘关系较近;（2）卵翅蝗亚科与稻蝗亚科亲缘关系较近,建议卵翅蝗亚科似乎应归入稻蝗亚科中,板胸蝗亚科与这两个亚科的关系较近;（3）黑蝗亚科和秃蝗亚科似乎应合并为一个亚科;（4）切翅蝗亚科的4个属未聚在一起,表明这些属的区别较大,不是一个单系群;（5）黑蝗亚科和秃蝗亚科关系较近,且与本研究中其他几个亚科的亲缘关系相对较远。研究结果表明COⅡ基因在解决斑腿蝗科的亚科以下属种间的系统发育关系时是一个有效的分子标记。     

杜鹃花科白珠树属分子系统学和生物地理学研究进展

白珠树属(Gaultheria) 在杜鹃花科(Ericaceae)系统演化中占有十分重要的地位, 其系统位置和演化关系一直备受争议。最近的分子系统学研究认为, 白珠树属已经不再属于传统上的越橘亚科(Vaccinioideae)的綟木族(Andromedeae), 而是与一些相关属组成了白珠树族(Gaultherieae)。对白珠树属产于美洲的类群和相关类群的分子系统学的初步研究则表明, 该属与Diplycosia、Tepuia和Pernettya等属(均为“常绿类群”)关系密切, 可能应将这几个属并入到白珠树属中, 但其属下分类系统关系还需要对产于亚洲的类群进行深入的研究后才能确定。白珠树属与其近缘属的进化历史和生物地理学关系较为复杂, 与杜鹃花科其他大多数属不同, 白珠树属为典型的环太平洋分布。关于白珠树属的起源问题存在两种不同的推测: 一种观点认为该属起源于南半球的冈瓦纳古陆; 另一种观点则认为其起源于北半球的劳亚古大陆。本文概述了近年来白珠树属的分子系统学和生物地理学研究进展, 并对该属尚存的一些问题进行了讨论。     

The diversification of the northern temperate woody flora – A case study of the Elm family (Ulmaceae) based on phylogenomic and paleobotanical evidence

Ulmaceae is a woody family widespread in northern temperate forests. Despite the ecological importance of this family, its phylogeny and biogeographic history are poorly understood. In this study, we reconstruct phylogenetic relationships within the family and infer spatio-temporal diversification patterns based on chloroplast genome (complete cpDNA) and nuclear ribosomal DNA sequences (nrDNA). The seven Ulmaceae genera are resolved in two main clades (temperate vs. tropical) by both cpDNA and nrDNA sequences. The temperate clade includes four genera, Hemiptelea, Zelkova, Planera, and Ulmus. The relationships among Planera and other genera are controversial because of inconsistent topologies between plastid and nuclear data. The tropical clade includes three genera ((Ampelocera, Phyllostylon), Holoptelea). Molecular dating and diversification analyses show that Ulmaceae originated in the Early Cretaceous (ca. 110–125 Ma) with the main lineages establishing from the Late Cretaceous to the early Eocene. The diversification rate slowed during the middle to the late Paleogene (ca. 23–45 Ma), followed by a rapid diversification of the East Asian temperate group in the Neogene, congruent with a global cooling event. The ancestral state optimization analysis suggests an East Asian origin of the temperate Ulmaceae clade during the Paleocene, which is consistent with the fossil record. Both phylogenomic and fossil evidence support East Asia as a center of origin and diversification for the temperate woody lineages.     

Molecular phylogeny and geographic distribution of wood-feeding cockroaches in East Asian Islands

Molecular phylogenetic relationships of the wood-feeding cockroach genera Salganea and Panesthia (Blaberidae; Panesthiinae) in East Asian Islands (Ryukyu archipelago and Taiwan Island) were analyzed based on the DNA sequence of the complete mitochondrial cytochrome oxidase II gene. Unweighted parsimony analysis resulted in high bootstrap support for relationships within Panesthia taxa; however, some nodes were unresolved between members of Salganea. Comparison of the number of transitions and transversions with genetic distance at each codon position suggested that saturation of third-codon substitutions has occurred between certain pairs of taxa. Consequently, differential weighting of substitutions at these sites was performed, which resulted in a substantial increase in resolution of Salganea relationships. The inferred phylogenies for both genera displayed good correspondence to the geographical locations of populations but however did not agree with previous subspecies designations based on morphological characters. It appears that both cockroach genera invaded the Ryukyu archipelago from the Taiwan region via a land-bridge present in the Miocene period. Invasion of the main islands of Japan by these cockroaches most likely occurred before the formation of the Tokara Tectonic Strait. Our study suggests that several barriers to gene flow have arisen and persisted over the past approximately 10 million years, which have caused segregation and vicariant speciation of the cockroach taxa of this region.     

Molecular phylogeny of Palaearctic genera of Gomphocerinae grasshoppers (Orthoptera, Acrididae)

Abstract.  Molecular phylogenetic methods were used to examine morphologically based hypotheses concerning the taxonomic structure and relationships of the grasshopper subfamily Gomphocerinae. Two mitochondrial gene (cytochrome b and cytochrome oxidase subunit I) sequences were determined for twenty-five species representing eleven Palaearctic genera. The studied Gomphocerinae species constituted a monophyletic group; furthermore, the earlier division of Gomphocerinae into tribes was supported, with each tribe monophyletic. There was no support for various systems uniting Stenobothrini and Gomphocerini into one tribe. Two separate clusters were discerned in Gomphocerini and two tribes were distinguished – Gomphocerini (genera Aeropus , Stauroderus , Chorthippus ) and Stenobothrini (genera Omocestus , Stenobothrus ).     

Plasma concentrations of vitamin E in six species of bustard (Gruiformes: Otididae)

Vitamin E (measured as alpha-tocopherol) and cholesterol concentrations were determined in plasma samples collected from 86 clinically healthy captive adult bustards of six species and 23 captive juveniles (6-12 mo old) of two of these species. Adult houbara bustards (Chlamydotis undulata macqueenii) had higher plasma alpha-tocopherol concentrations than juveniles (adult: mean +/- SE, 11.07 +/- 0.41 micrograms/ml, n = 32; juvenile: 6.33 +/- 0.48, n = 12) and higher alpha-tocopherol: cholesterol ratios (adult: 6.09 +/- 0.44, n = 12; juvenile: 2.94 +/- 0.22, n = 11). No age difference was evident for kori bustard (Ardeotis kori) plasma alpha-tocopherol concentrations (adult: 4.43 +/- 0.42, n = 21; juvenile: 4.46 +/- 0.26, n = 11) or alpha-tocopherol: cholesterol ratios (adult: 3.67 +/- 0.44, n = 20; juvenile: 3.71 +/- 0.36, n = 11). Adult houbara bustards had significantly higher (P < 0.01) alpha-tocopherol concentrations compared with adult rufous-crested (Eupodotis ruficrista; 6.64 +/- 0.33, n = 19) and white-bellied (Eupodotis senegalensis; 7.75 +/- 0.81, n = 8) bustards, but similar alpha-tocopherol: cholesterol ratios (rufous-crested: 5.56 +/- 0.32, n = 18; white-bellied: 5.83 +/- 0.43, n = 8). Juvenile houbara bustards had higher plasma alpha-tocopherol concentrations than juvenile kori bustards but similar alpha-tocopherol:cholesterol ratios. Adult houbara bustard plasma alpha-tocopherol levels and alpha-tocopherol:cholesterol ratios did not differ significantly between sexes. The vitamin E status of adult bustards appeared to be influenced by environmental conditions that varied due to species-specific husbandry regimens, but no clear relationship was seen with dietary vitamin E levels. Juvenile bustards did not have higher vitamin E levels than adults, despite being maintained on four-fold dietary vitamin E concentrations and in similar environmental conditions. This paper presents the first published data for plasma vitamin E concentrations in bustards. The plasma alpha-tocopherol and cholesterol concentrations and alpha-tocopherol:cholesterol ratios of captive bustards were similar to those previously reported for omnivorous avian species. Further research is required to determine which components of the identified environmental conditions affect bustard vitamin E status and to confirm whether differences exist between species independent of the variation in their management regimes.     

Phylogenetic relationships and molecular evolution of woody forest tree family Aceraceae based on plastid phylogenomics and nuclear gene variations

The forest tree family Aceraceae is widespread in the northern hemisphere and it has ecological and economic importance. However, the phylogenetic relationships and classifications within the family are still controversial due to transitional intraspecific morphological characteristics and introgression hybridization among species. In this study, we determined the evolutionary relationships and molecular evolution of Aceraceae based on plastid phylogenomics and two nuclear gene variations. Phylogenetic analysis based on the plastid genomes suggested that Aceraceae species can be divided into two larger sub-clades corresponding to the two genera Acer and Dipteronia. Conjoint analysis of the plastid and nuclear gene sequences supported the classification with two genera in the family. Molecular dating showed that the two genera diverged 60.2 million years ago, which is generally consistently with previously reported results. Divergence hotspots and positively selected genes identified in the plastid genomes could be useful genetic resources in Aceraceae.     

Complete Plastid Genome Sequencing of Trochodendraceae Reveals a Significant Expansion of the Inverted Repeat and Suggests a Paleogene Divergence between the Two Extant Species

The early-diverging eudicot order Trochodendrales contains only two monospecific genera, Tetracentron and Trochodendron. Although an extensive fossil record indicates that the clade is perhaps 100 million years old and was widespread throughout the Northern Hemisphere during the Paleogene and Neogene, the two extant genera are both narrowly distributed in eastern Asia. Recent phylogenetic analyses strongly support a clade of Trochodendrales, Buxales, and Gunneridae (core eudicots), but complete plastome analyses do not resolve the relationships among these groups with strong support. However, plastid phylogenomic analyses have not included data for Tetracentron. To better resolve basal eudicot relationships and to clarify when the two extant genera of Trochodendrales diverged, we sequenced the complete plastid genome of Tetracentron sinense using Illumina technology. The Tetracentron and Trochodendron plastomes possess the typical gene content and arrangement that characterize most angiosperm plastid genomes, but both genomes have the same unusual ∼4 kb expansion of the inverted repeat region to include five genes (rpl22, rps3, rpl16, rpl14, and rps8) that are normally found in the large single-copy region. Maximum likelihood analyses of an 83-gene, 88 taxon angiosperm data set yield an identical tree topology as previous plastid-based trees, and moderately support the sister relationship between Buxaceae and Gunneridae. Molecular dating analyses suggest that Tetracentron and Trochodendron diverged between 44-30 million years ago, which is congruent with the fossil record of Trochodendrales and with previous estimates of the divergence time of these two taxa. We also characterize 154 simple sequence repeat loci from the Tetracentron sinense and Trochodendron aralioides plastomes that will be useful in future studies of population genetic structure for these relict species, both of which are of conservation concern.     

Systematic Position of the African Dormouse Graphiurus (Rodentia, Gliridae) Assessed from Cytochrome b and 12S rRNA Mitochondrial Genes

Gliridae is a small family of rodents including three subfamilies: the Eurasian Glirinae (with three genera) and Leithiinae (with four genera) and the African Graphiurinae (with a single genus). Phylogenetic relationships among these eight genera are not fully resolved based on morphological characters. Moreover, the genus Graphiurus is characterized by numerous peculiar features (morphological characters and geographical distribution), raising the question of its relationships to the family Gliridae. The phylogenetic position of Graphiurus and the intra-Gliridae relationships are here addressed by a molecular analysis of 12S RNA and cytochrome b mitochondrial gene sequences for six glirid genera. Phylogenetic analyses are performed with three construction methods (neighbor-joining, maximum parsimony and maximum likelihood) and tests of alternative topologies with respect to the most likely. Our analyses reveal that Graphiurus is clearly a member of the Gliridae, refuting the hypothesis that the family could be paraphyletic. Among Gliridae, phylogenetic relationships are poorly resolved: the Leithiinae could be monophyletic, there is no support for the subfamily Glirinae, and the closest relative of Graphiurus is not identified. The inclusion of Graphiurus among Gliridae allows us to postulate that its hystricomorphous condition has been achieved convergently with other hystricomorphous rodents.     

Dimensions and composition of eggs from captive bustards (Gruiformes: Otididae): houbara (Chlamydotis undulata), rufous‐crested (Eupodotis ruficrista), and kori (Ardeotis kori)

This study sought to increase understanding of the size and composition of eggs from two subspecies of houbara bustard (Chlamydotis undulata macqueenii and C. u. undulata). Eggs from the rufous‐crested bustard (Eupodotis ruficrista) and kori bustard (Ardeotis kori) were also examined for comparison. Infertile eggs were collected from captive birds; egg mass and linear dimensions were recorded, and egg component masses were determined wet and dry. Significant differences were observed in the composition of the eggs from the two houbara subspecies. Despite being smaller in size, eggs from the macqueenii subspecies had a relatively larger yolk (and relatively less albumen) than eggs from the undulata subspecies. The relative composition of the rufous‐crested and kori bustard eggs showed patterns similar to that of the undulata eggs. For the houbara bustards, changes in initial egg mass (IEM) were associated with changes in egg length more than egg breadth, and changes in egg length and breadth appeared to be due more to increases in albumen mass than to increases in yolk mass. Zoo Biol 21:337–346, 2002. © 2002 Wiley‐Liss, Inc.     

The African warbler genus Hyliota as a lost lineage in the Oscine songbird tree: molecular support for an African origin of the Passerida

The African genus Hyliota includes three or four species of warbler-like birds of uncertain phylogenetic affinities, as it has historically been placed in different avian families that are now known to represent unrelated lineages: Malaconotidae (bush-shrikes), Platysteiridae (batises and wattle-eyes), Muscicapidae (Old World flycatchers) and Sylviidae (Old-World Warblers). To assess the affinities of Hyliota we sequenced a mitochondrial protein-coding gene (ND2, 1018bp) and a nuclear intron (myoglobin intron-2, 685bp). Our analyses suggest that all previous hypotheses concerning the affinities of Hyliota are erroneous. Instead, Hyliota represents a basal branch in the Passerida radiation with no close relatives. Our results, which also include analyses of relationships among other of other atypical songbird genera, lend support to an African origin of the Passerida songbird radiation.     

A preliminary phylogeny of the 'didymocarpoid Gesneriaceae' based on three molecular data sets: Incongruence with available tribal classifications

The 'didymocarpoid Gesneriaceae' (traditional subfam. Cyrtandroideae excluding Epithemateae) are the largest group of Old World Gesneriaceae, comprising 85 genera and 1800 species. We attempt to resolve their hitherto poorly understood generic relationships using three molecular markers on 145 species, of which 128 belong to didymocarpoid Gesneriaceae. Our analyses demonstrate that consistent topological relationships can be retrieved from data sets with missing data using subsamples and different combinations of gene sequences. We show that all available classifications in Old World Gesneriaceae are artificial and do not reflect natural relationships. At the base of the didymocarpoids are grades of clades comprising isolated genera and small groups from Asia and Europe. These are followed by a clade comprising the African and Madagascan genera. The remaining clades represent the advanced Asiatic and Malesian genera. They include a major group with mostly twisted capsules. The much larger group of remaining genera comprises exclusively genera with straight capsules and the huge genus Cyrtandra with indehiscent fruits. Several genera such as Briggsia, Henckelia, and Chirita are not monophyletic; Chirita is even distributed throughout five clades. This degree of incongruence between molecular phylogenies, traditional classifications, and generic delimitations indicates the problems with classifications based on, sometimes a single, morphological characters.     

First phylogeny of predatory flower flies (Diptera, Syrphidae, Syrphinae) using mitochondrial COI and nuclear 28S rRNA genes: conflict and congruence with the current tribal classification

The family Syrphidae (Diptera) is traditionally divided into three subfamilies. The aim of this study was to address the monophyly of the tribes within the subfamily Syrphinae (virtually all with predaceous habits), as well as the phylogenetic placement of particular genera using molecular characters. Sequence data from the mitochondrial protein-coding gene cytochrome c oxidase subunit I ( COI ) and the nuclear 28S ribosomal RNA gene of 98 Syrphinae taxa were analyzed using optimization alignment to explore phylogenetic relationships among included taxa. Volucella pellucens was used as outgroup, and representatives of the tribe Pipizini (Eristalinae), with similar larval feeding mode, were also included. Congruence of our results with current tribal classification of Syrphinae is discussed. Our results include the tribe Toxomerini resolved as monophyletic but placed in a clade with genera Ocyptamus and Eosalpingogaster . Some genera traditionally placed into Syrphini were resolved outside of this tribe, as the sister groups to other tribes or genera. The tribe Bacchini was resolved into several different clades. We recovered Paragini as a monophyletic group, and sister group of the genus Allobaccha . The present results highlight the need of a reclassification of Syrphinae.
© The Willi Hennig Society 2008.     

华东天目山脉、黄山山脉、大别山脉竹类植物区系分析,兼论区系的起源与扩散

华东天目山脉、黄山山脉、大别山脉竹类植物较为丰富,分别有10属/75种(含种下等级)、8/49、7/30.通过对属、种的分布型分析,前二者竹类植物区系属于典型的华东区系,起源的时间不迟于早第三纪的始新世;而大别山脉虽仍属华东区系的范畴,因渗入了不少华中区系的成分,已具有某些经向过渡性特征,且起源的时间较晚.这3个山脉的竹类植物区系均具有显著的亚热带性质.天目山脉不仅是刚竹属Phyllostachys和短穗竹属Brachystachyum的分化变异中心,也极有可能就是它们的起源中心,但它们自此地起源后的散布方式有所不同,刚竹属在我国亚热带为四周放射状顺序渐进,扩散的范围颇广;短穗竹属存在东西南北4条散布路线,但向各方扩散的距离相差甚远.这些山脉与华东其他地区竹类植物区系联系密切,与华中竹类植物区系也有一定的联系,但与华南、西南等地竹类植物区系联系微弱.从地理位置和区系组成来看,黄山山脉的竹类植物区系来源于天目山脉,大别山脉的竹类植物区系又来源于黄山山脉,前者都是在后者扩展的基础上融合了其他区系的一些成分后发展而成,大别山脉又是北方秦岭以东广大丘陵平原地区竹类植物区系的发祥地.     

A molecular assessment of phylogenetic relationships and lineage accumulation rates within the family Salamandridae (Amphibia, Caudata)

We examine phylogenetic relationships among salamanders of the family Salamandridae using approximately 2700 bases of new mtDNA sequence data (the tRNALeu, ND1, tRNAIle, tRNAGln, tRNAMet, ND2, tRNATrp, tRNAAla, tRNAAsn, tRNACys, tRNATyr, and COI genes and the origin for light-strand replication) collected from 96 individuals representing 61 of the 66 recognized salamandrid species and outgroups. Phylogenetic analyses using maximum parsimony and Bayesian analysis are performed on the new data alone and combined with previously reported sequences from other parts of the mitochondrial genome. The basal phylogenetic split is a polytomy of lineages ancestral to (1) the Italian newt Salamandrina terdigitata, (2) a strongly supported clade comprising the "true" salamanders (genera Chioglossa, Mertensiella, Lyciasalamandra, and Salamandra), and (3) a strongly supported clade comprising all newts except S. terdigitata. Strongly supported clades within the true salamanders include monophyly of each genus and grouping Chioglossa and Mertensiella as the sister taxon to a clade comprising Lyciasalamandra and Salamandra. Among newts, genera Echinotriton, Pleurodeles, and Tylototriton form a strongly supported clade whose sister taxon comprises the genera Calotriton, Cynops, Euproctus, Neurergus, Notophthalmus, Pachytriton, Paramesotriton, Taricha, and Triturus. Our results strongly support monophyly of all polytypic newt genera except Paramesotriton and Triturus, which appear paraphyletic, and Calotriton, for which only one of the two species is sampled. Other well-supported clades within newts include (1) Asian genera Cynops, Pachytriton, and Paramesotriton, (2) North American genera Notophthalmus and Taricha, (3) the Triturus vulgaris species group, and (4) the Triturus cristatus species group; some additional groupings appear strong in Bayesian but not parsimony analyses. Rates of lineage accumulation through time are evaluated using this nearly comprehensive sampling of salamandrid species-level lineages. Rate of lineage accumulation appears constant throughout salamandrid evolutionary history with no obvious fluctuations associated with origins of morphological or ecological novelties.     

Age-related hematologic changes in captive-reared houbara,white-bellied,and rufous-crested bustards

Blood samples were obtained at monthly intervals between April 1994 and March 1996 from captive-bred houbara (Chlamydotis undulata macqueenii), rufous-crested (Eupodotis ruficrista gindiana), and white-bellied (Eupodotis senegalensis) bustards from 4-24 wk of age. Hematology investigations were conducted to determine age-related changes and to establish reference values for growing chicks of these species. There were significant age-related changes in hematocrit, hemoglobin, and red cell count in young birds compared with those of adults. White cell counts (lymphocytes and monocytes) were higher in juvenile birds, compared with adult values.