Molecular phylogenetic analysis shows that <Emphasis Type="Italic">Amanita ponderosa</Emphasis> and <Emphasis Type="Italic">A. curtipes</Emphasis> are distinct species

Amanita curtipes and A. ponderosa are two Mediterranean taxa sharing a number of morphological features as well as their habitat. Their synonymy or variety status has been proposed by several authors. To clarify this taxonomic issue we have sequenced the D1-D2 domains of the 28S rRNA gene as well as the complete ITS1-5.8S-ITS2 region of several specimens of the two species collected in Spain, and aligned these sequences with those from other Amanita species. Molecular phylogenetic analysis based on the two regions revealed that A. ponderosa and A. curtipes are clearly distinct species. The distribution of Amanita species in the phylogenetic trees was consistent with the division of the genus in subgenera and sections as proposed by previous authors. Sequences of A. ponderosa and A. curtipes were grouped in a monophyletic cluster together with other species of the section Amidella. However, A. ponderosa was closer to other species in the section, such as A. peckiana and A. volvata, than to A. curtipes. We also indicate the macromorphological characters that are most useful to reliably distinguish A. ponderosa and A. curtipes.     

高温胁迫对水稻花粉粒性状及花药显微结构的影响

对两个耐热性不同的水稻品系进行高温处理(8:00～17:00,37℃,17:00～8:00,30℃),测定了高温胁迫对水稻花粉粒性状及花药显微结构的影响.结果表明,高温胁迫导致花药开裂、花粉活力、花粉萌发率和柱头上花粉粒数的显著下降,花粉粒直径增大.高温下耐热品系996的花药开裂、花粉活力、花粉萌发率和柱头上花粉粒数明显高于热敏感品系4628,这表明耐热品系996在高温胁迫条件下能保持较好地花粉散落特性和花粉萌发特性,是其耐热性的生理基础;高温下耐热品系996的花药壁的表皮细胞排列较整齐,细胞间隙小;药隔维管束较大,维管束鞘细胞排列整齐,簿壁细胞多且排列整齐,木质部和韧皮部清楚可见;而热敏感品系4628花药壁的表皮细胞形状不规则,排列疏松,细胞间隙大,药隔维管组织受到很大程度破坏,维管束鞘细胞形状异常,排列紊乱,木质部和韧皮部界限不清.     

模拟阴天对南美白对虾养殖水体理化及其生长指标的影响

为探索阴天对南美白对虾(Penaeus vannamei Boon)养殖水体理化及其生长指标的影响, 实验采用黑色遮荫网模拟阴天弱光环境对南美白对虾进行遮荫实验, 设置遮荫组与对照组各5个平行, 实验周期7周。遮荫组采用黑色遮荫网交替性遮荫, 即第1、第3、第5、第7周遮荫, 第2、第4、第6周曝光, 对照组正常养殖。结果显示: 遮荫组与对照组的pH、DO、Chl. a、 -N、NH₃-N、 -N、 -N及 -P的浓度在遮荫处理下具有显著性差异(P<0.05), Chl. a、 -N及 -P的浓度具有明显的波动性, 表现为遮荫时Chl. a的浓度极显著降低(P<0.01), -N、 -P的浓度极显著升高(P<0.01); 曝光时遮荫组Chl. a的浓度较遮荫时升高, -N的浓度极显著降低(P<0.01), -P浓度的增长幅度降低, 此时遮荫组与对照组Chl. a、 -N及 -P的浓度无显著差异。 -N的浓度在实验前5周, 遮荫组高于对照组, 第6、7周对照组高于遮荫组。 -N浓度在整个实验周期中则是遮荫组高于对照组。南美白对虾生长指标结果显示: 两个组生长指标具有显著性差异。研究表明: 妨害南美白对虾生长的主要是NH₃-N, 然后是 -N; 藻类可间接促进南美白对虾生长。遮荫处理抑制藻类吸收养殖水体中的有毒离子、恶化南美白对虾的生长环境并危害对虾的生存、生长。     

Viability and expression of sexual ornaments in the barn swallow Hirundo rustica: a meta‐analysis

Sexual selection results in the evolution of exaggerated secondary sexual characters that can entail a viability cost. However, in species where sexual ornaments honestly reflect individual quality, the viability cost of secondary sexual characters may be overwhelmed by variation in individual quality, leading to expect that individuals with the largest secondary sexual characters show higher, rather than lower viability. Here, we used meta‐analyses to test whether such expected positive relationship between sexual ornamentation and viability exists in the barn swallow Hirundo rustica, which is one of the most studied model species of sexual selection under field conditions. We found a mean positive effect size of viability in relation to the expression of secondary sexual characters of 0.181 (CI: 0.084–0.278), indicating that in this species the more ornamented individuals are more viable, and therefore of high quality. Analyses of moderator variables showed similar effects in males and females, the H. r. rustica subspecies rather than others and tail length rather than other secondary sexual characters. Future research emphasis on other subspecies than the European one and secondary sexual characters than tail length may help identify the sources of heterogeneity in effect sizes.     

Revision of Australian Matini diving beetles based on morphological and molecular data (Coleoptera,Dytiscidae, Matinae), with description of a new species

Morphological characters and mitochondrial DNA sequence data were used to revise the Australian diving beetles in the genera Allomatus Mouchamps, 1964 and Batrachomatus Clark, 1863. As a result of these studies Allomatus syn. n. is synonymised with Batrachomatus, and Allomatus nannup Watts, 1978 from SW Australia and Allomatus wilsoni Mouchamps, 1964 from SE Victoria are transferred to Batrachomatus. The four Australian Matini species knownso far are re-described, and Batrachomatus larsoni sp. n. from the Windsor Tableland in NE Queensland is described. After more than 40 years Batrachomatus wilsoni has been re-discovered in two rivers in Victoria. We delineate the species using traditionally employed morphological structures such as in the male genitalia and body size, shape and colour pattern, as well as mitochondrial cox1 sequence data for 20 individuals. Important species characters (median lobes, parameres and colour patterns) were illustrated. We provide an identification key and outline distribution and habitat preferences of each species. All Australian Matini are lotic, inhabiting permanent and intermittent streams, creeks and rivers.     

Growth of the first antler in Iberian red deer (<Emphasis Type="Italic">Cervus elaphus hispanicus</Emphasis>)

In this study, we describe the process of pedicle and first antler growth in Iberian red deer (Cervus elaphus hispanicus) and document relationships among body development, maternal milk supply and composition, and maternal weight on the length of first antlers. Antler length of 53 males of Iberian red deer was measured every 2 weeks from birth to 20 months of age. Deer weight, age, and the date of occurrence of the major events during the antler growth cycle were also recorded. The first evidence of pedicle development occurred when the animals were 38.0 ± 0.6 weeks old and weighed 60.7 ± 0.9 kg. Antler cleaning took place at a mean age of 63.8 ± 0.7 weeks and a mean weight of 91.5 ± 1.8 kg. The antler growth period lasted 16.7 ± 0.4 weeks, and the cleaning period lasted 5.1 ± 0.4 weeks. First antler growth followed a sigmoid curve, reaching a final length of 38.3 ± 1.0 cm. Antler length was positively correlated with body weight during the antler growth cycle. Additionally, the final length of the first antler was related to total milk yield, date of antler growth initiation, body weight at 6 months of age, and the antler growth time interval.     

中国大陆沿海新记录种——卷眼斑鲆（Pseudorhombus oculocirris）

斑鲆属（Pseudorhombus, Bleeker, 1862）隶属于鲽形目（Pleuronectiforms）牙鲆科（Paralichthyidae）,根据Eschmeyer’s Catalog of Fishes记录有效种类有25种;根据李思忠等（1995）的《中国动物志：硬骨鱼纲 鲽形目》记载,目前在中国大陆海域有标本记录的有11种。本研究在2007年到2021年在海南的文昌、陵水和三亚分别采集到了9尾有眼侧有5个眼状斑纹的标本,并和该属25种鱼类的原始形态特征进行了比较。比对结果发现,该样品符合Amaoka（1969）定名的卷眼斑鲆（P. oculocirris Amaoka, 1969）形态特征。该种类目前只在日本和越南有报道,本研究是首次在中国大陆海域采集,故为新记录种。本研究结合卷眼斑鲆原始描述、相关文献和采集到的9尾标本的形态特征对该种类进行了详细的再描述,并首次提供了线粒体分子条形码（GenBank登录号为OL307681、OL307682和OL307683）。该种的主要形态特征为背鳍65–76;臀鳍50–57;有眼侧胸鳍11–13,无眼侧胸鳍10–12;尾鳍条2 + 13 + 2;第一鳃弓鳃耙4–7 + 17–20;侧线鳞71–82;脊椎骨10 + 26 = 36;背鳍前边几个鳍条稍长且基部只有1/5–1/3连有鳍膜,下眼上缘具有指状皮突。本研究的发现进一步扩大了该种的分布范围和提供了种类鉴定的分子依据,本报道将会为牙鲆科鱼类生物多样性和系统演化研究提供科学依据。     

Molecular taxonomic identification in the absence of a ‘barcoding gap’: a test with the endemic flora of the Canarian oceanic hotspot

We use a comprehensive subset of Canarian angiosperms corresponding to 23 families, 35 genera and 60 Canarian endemic taxa to test whether this flora is suitable to taxonomic identification with the two proposed plant DNA barcode sequences and whether these sequences may reveal the existence of cryptic species overlooked by morphology. The rate of discrimination success between the insular congeneric samples using the rbcL+matK combination and a ‘character‐based’ approach (where we use only the combination of nucleotide positions in an alignment that allows unambiguous species identification) is higher (82.29%) than that obtained with the ‘distance‐based’ approach (80.20%) used by the CBOL Plant Working Group in 2009 and also when compared with tests conducted in other floras. This suggests that the molecular identification of the Canarian endemic flora can be achieved as successfully as in other floras where the incidence of radiation is not as relevant. The facts that (i) a distance‐based criterion was unable to discriminate between congeneric and conspecific comparisons and (ii) only the character‐based discrimination criterion resolved cases that the distance‐based criterion did not, further support the use of a character discrimination approach for a more efficient DNA barcoding of floras from oceanic islands like the Canaries. Thus, a barcoding gap seems not to be necessary for the correct molecular characterization of the Canarian flora. DNA barcodes also suggest the possible existence of cryptic taxa to be further investigated by morphology and that the current taxonomic status of some of the taxa analysed may need revision.