Early development of the endangered freshwater goby, Rhinogobius sp. BI (Gobiidae)

The early development of the endangered freshwater goby, Rhinogobius sp. BI (ogasawara-yoshinobori in Japanese), was described in the course of a serial rearing experiment over generations as ex situ preservation. The eggs, measuring 2.0 mm in long diameter and 0.7 mm in short diameter, were elliptical with a colorless transparent chorion, a slightly yellowish yolk, and some oil globules. Hatching occurred naturally at 6 to 7 days after spawning at 24.0°C. Newly hatched larvae, measuring 3.2–3.4 mm in total length (TL), had opened mouth and a globular yolk sac. The yolk was completely absorbed at 3.5 mm TL (5 days after hatching). Notochord flexion initiated at 5.7 mm TL (18 days) and finished at <9.1 mm TL (30 days). First dorsal fin began to form in postflexion larvae at 10.0 mm TL (40 days), and a full complement was attained at 11.6 mm TL (45 days). Second dorsal fin emerged at 5.7 mm TL (18 days); full count was attained and segmentation initiated at 9.1 mm TL (30 days). Anal fin anlage appeared at 5.7 mm TL (18 days); its ray count was completed and segmentation initiated at 9.1 mm TL (30 days), and branching at 15.6 mm TL (60 days). Caudal fin support appeared at 4.5 mm TL (15 days); segmentation initiated at 6.0 mm TL (24 days) and branching at 10.0 mm TL (40 days). Fanlike pectoral fin present in newly hatched larvae. Pectoral fin rays appeared at 10.0 mm TL (40 days), and its ray count completed at 15.6 mm TL (60 days). Pelvic fin projected at 9.1 mm TL (30 days), and a sucking disc partially formed at 11.6 mm TL (45 days). Aggregate numbers of all fin rays were completed at 15.6 mm TL in 60 days after hatching. Pelagic period continued for about 40 days, and settlement was completed in postflexion larvae at 45 days.     

Determinants of male mating success in a natural population of a stream goby of the genus Rhinogobius

The mating success of individually identified males of a stream goby, Rhinogobius sp. CB (cross‐band type), was recorded over one breeding season. One to 3 year‐old males were active in mating, but 3 year‐old males, which accounted for 36% of the population, amounted to c . 70% of the total males guarding eggs in the nest. Three quarters of the breeding males had only one brooding cycle, but the others had two or three. All the latter males changed their nest sites between cycles within a riffle. In 1 and 2 year‐old males, the number of brooding cycles contributed more to the mating success than egg mass size in one brooding cycle. For mating success of 3 year‐old males, the egg mass size in one brooding cycle, which can be enhanced by spawning with a large female or multiple females, was as important as the number of brooding cycles. These male reproductive tactics could be attributed to the age‐related ability of nest construction and mate acquisition.     

Isolation and characterization of microsatellite DNA loci in Aquilegia sp.

We obtained a microsatellite‐enriched genomic library isolated from the tissue of a single columbine (Aquilegia sp.) plant taken from a southwestern USA natural population. The primers developed for these microsatellite loci performed consistently in polymerase chain reactions and yielded multiallelic genotypes with relatively high observed heterozygosities. We describe polymerase chain reaction primers and conditions to amplify 16 unique, codominant di‐, tri‐ and tetra‐nucleotide microsatellite DNA loci so that other population biology researchers using columbine natural populations as a model system may benefit.     

Development and multiplex PCR amplification of new microsatellite markers for the freshwater fish,ayu (Plecoglossus altivelis)

Multiplex polymerase chain reaction (PCR) technique has recently been applied to gain many advantages in molecular genetics. The present study focused on the development of 15 new microsatellite markers with multiplex PCR systems in ayu, Plecoglossus altivelis, an important freshwater fish in Japan. All loci were followed Mendelian inheritance in 27 F1 progeny except for the one locus. The number of alleles per locus ranged from nine to 44 and the observed heterozygosities ranged from 0.680 to 0.980 in 50 unrelated individuals. The results indicate that these new microsatellite markers are useful for studies of linkage mapping and population genetics for the species.     

Characterization of 14 polymorphic microsatellite loci for the lesser horseshoe bat,Rhinolophus hipposideros (Rhinolophidae,Chiroptera)

Fourteen polymorphic microsatellites isolated in the lesser horseshoe bat, Rhinolophus hipposideros, are described. A subset of eight loci successfully coamplified in a multiplex polymerase chain reaction (PCR), and allowed to confirm that expected heterozygosity was relatively high for the eight loci (0.56–0.83). This set of eight microsatellites indeed permits to build genetic tags that distinguish all individuals in colonies consisting of up to more than 1000 individuals.     

PCR multiplexing of nuclear microsatellite loci inQuercus species

Simple sequence repeats have become the tool of choice in a wide range of studies of forest trees. Despite frequent use of multicolor fluorescent labeling DNA fragment analyzers, there are few procedures that reduce time and cost of the analyses by PCR multiplexing. Here we present an example of 2 multiplexes of 7 unlinked nuclear microsatellite loci to increase the efficiency of genotyping of large samples of oaks, which is extremely useful in population genetic studies.     

中国浙江省吻虾虎鱼属一新种(鲈形目:虾虎鱼科)

描述分布于浙江省武义县武义江的吻虾虎鱼1新种,定名为武义吻虾虎鱼(Rhinogobius wuyiensis)。该虾虎鱼在头部斑纹上与雀斑吻虾虎鱼(R.lentiginis)相近,但有如下特征可区别于相近种:具眼肩胛骨管及前鳃盖管(vs.无任何感觉管孔);椎骨数10 16=26(vs.27);臀鳍分支鳍条7-9(vs.6-7);头部斑点大小不等且不规则,常呈线状交织(vs.具规则的小圆斑);鳃盖条部内侧无斑点(vs.密布小点)。     

Egg and clutch sizes of a goby Rhinogobius giurinus in the Aizu River, Kii Peninsula, Japan

Egg and clutch sizes, and gonad somatic index (GSI) at maturity of the amphidromous goby Rhinogobius giurinus were examined in the Aizu River, Wakayama Prefecture, Japan. The goby tended to have a larger clutch size, with smaller eggs, and matured at the lower GSI, compared with those in the three sympatric amphidromous species of R. brunneus complex. Higher water temperature and abundant food conditions may affect the optimal egg size in R. giurinus. Besides, higher larval survival rate during downstream migration may affect lower GSI at maturity in this goby that usually inhabits lower reaches of the river.     

Isolation and characterization of polymorphic microsatellite loci from the Dungeness crab Cancer magister

The Dungeness crab, Cancer magister, is the focus of one of the most intensely harvested fisheries in North America. Given its economic importance, there is considerable interest in assessing the degree and spatial pattern of genetic structure in C. magister. To that end, we developed a series of 17 hypervariable microsatellite loci. Six of these 17 loci could be amplified in a single multiplex PCR reaction. Using dye‐labelled primers all six loci can be coamplified and scored simultaneously on an automated sequencer. The ability to multiplex multiple loci greatly increases the ease and speed of genotyping for this species.     

Isolation and characterization of polymorphic microsatellite loci in the freshwater fishes Telestes souffia and Telestes muticellus (Teleostei: Cyprinidae)

Ten novel polymorphic microsatellites (seven with perfect motifs) were isolated from vairone species (Telestes souffia and Telestes muticellus), which are endangered European cyprinid species. Together with 11 previously published cyprinid-specific loci, five multiplex sets were optimized, allowing the genotyping of 21 polymorphic loci. The level of genetic diversity was assessed in 97 individuals from the two species T. souffia and T. muticellus. We also successfully applied the 21 microsatellites to nine related species. These primers will thus be useful in assessing population structure of the vairone and other cyprinid species, with application for conservation issues and phylogeographical approaches.     

Isolation of microsatellite loci in the freshwater fish,the bitterling Rhodeus sericeus (Teleostei: Cyprinidae)

We isolated 30 microsatellites from the freshwater fish, the bitterling Rhodeus sericeus. Twenty‐three microsatellite sequences possessed sufficient flanking DNA from which to design primers. Twelve loci were characterized and all were found to be polymorphic. These loci were isolated and characterized as part of a project to investigate the consequences of male alternative mating tactics and sperm competition using the bitterling as a model species.     

Rhinogobius immaculatus,a new species of freshwater goby (Teleostei: Gobiidae) from the Qiantang River,China

A new freshwater goby, Rhinogobius immaculatus sp.nov., is described here from the Qiantang River in China. It is distinguished from all congeners by the following combination of characters: second dorsal-fin rays I, 7–9; anal-fin rays I, 6–8; pectoral-fin rays14–15; longitudinal scales 29–31; transverse scales7–9; predorsal scales 2–5; vertebrae 27(rarely 28);preopercular canal absent or with two pores; a red oblique stripe below eye in males; branchiostegal membrane mostly reddish-orange, with 3–6 irregular discrete or connected red blotches on posterior branchiostegal membrane and lower operculum in males; caudal-fin base with a median black spot; and no black blotch on anterior part of first dorsal fin in males.     

中国广东省虾虎鱼一新种——周氏吻虾虎鱼(Rhinogobius zhoui)(鲈形目:虾虎鱼科)

记述了分布于广东省海丰县莲花山溪流中的吻虾虎鱼属一新种,定名为周氏吻虾虎鱼Rhinogobius zhoui。该新种可由如下特征区别于相近种：第二背鳍条I, 8—9;臀鳍条I, 7—8;胸鳍条16—18;纵列鳞29—31;背鳍前鳞10—12;椎骨数10+16=26;成年雄性个体第一背鳍无黑斑,各奇鳍具宽大的亮白色边缘,颊部与鳃盖膜无斑纹,体侧具6—8个红色斑块。     

Isolation and characterization of 11 polymorphic microsatellite loci in the whitegirdled goby (Pterogobius zonoleucus) and cross-species amplification in the serpentine goby (P. elapoides)

Eleven polymorphic microsatellite markers were developed from a (CA)(n) -enrichment library of the whitegirdled goby (Pterogobius zonoleucus). Polymorphism at these loci ranged from 2 to 12 alleles, and observed and expected heterozygosities from 0.05 to 0.90 and from 0.05 and 0.86, respectively. All loci conformed to Hardy-Weinberg equilibrium, with no significant linkage disequilibrium between all locus pairs. Cross-species amplification tests were successful in P. elapoides, and most loci were polymorphic. These microsatellite markers will be useful in further population genetic studies of both species.     

Development of 14 multiplexed microsatellite loci for raccoons Procyon lotor

In order to complement ecological information with genetic data we isolated and characterized 14 polymorphic microsatellite markers from raccoons (Procyon lotor). Three multiplexed panels comprising the loci were developed and 29 individuals from a contiguous habitat patch in northern Indiana, USA were genotyped. The number of alleles per locus ranged from four to 18, and overall heterozygosities ranged from 0.31 to 1.00. One locus was identified as possibly being X‐linked, since males appeared to be hemizygous. Data generated using these markers will be used to further our understanding of small‐scale raccoon population dynamics in a highly fragmented landscape.     

Characterization of tetranucleotide microsatellite loci and development and validation of multiplex reactions for the study of right whale species (genus Eubalaena)

A North Atlantic right whale (Eubalaena glacialis) genomic library was developed and screened with a (GATA)₈ probe to identify tetranucleotide microsatellite loci. Sixteen characterized loci were polymorphic in North Atlantic and/or South Atlantic (Eubalaena australis) right whales, 12 being polymorphic in E. glacialis, and 15 in E. australis. Fourteen of these were combined with 21 other previously identified loci for a suite of 35 loci which can be used to increase resolution of genetic analyses of these species. Multiplex reactions were developed for genotyping samples at these loci, providing a method that is rapid, reliable and cost‐effective.     

The relative importance of substrate conditions as microhabitat determinants of a riverine benthic goby, Rhinogobius sp. OR (orange form) in runs

We examined the microhabitat determinants of the benthic goby Rhinogobius sp. OR (orange form) in runs by measuring fish density, and substrate and hydraulic variables at four sites in the middle and lower reaches of the Ado River, Japan. One of the four sites was located below a bridge pier in the lower reach and had coarser substrate than was typical there. This contributed to the elimination of the correlation between substrate condition and hydraulic variables by providing anomalous combinations of substrate and hydraulic variables. Using principal component analysis, the variables were divided into substrate and hydraulic components. A multiple regression analysis revealed that substrate variables explained more of the variance in fish density than hydraulic variables. We concluded that the density of this goby is determined by substrate conditions in runs, where the current velocity is lower and the stone shelter is scarcer than in riffles. The importance of substrate conditions, which can be easily masked by current velocity in natural settings, should not be neglected.     

Identification and characterization of 10 polymorphic microsatellite loci in the German cockroach,Blattella germanica

Primer sequences and initial characterization are presented for 10 microsatellite loci isolated from the German cockroach, Blattella germanica. In a sample of 30 individuals from a single population sample, all loci were polymorphic with two to 12 alleles segregating per locus and levels of observed heterozygosity ranging from 0.27 to 0.92. One locus showed a deficit of heterozygotes. Experimental conditions are described for polymerase chain reaction multiplexing, which enables the genotyping of eight loci in three electrophoretic runs consisting of one set of three and two sets of two markers. Seven primer sets cross‐amplify in the related Blattella asahinai.     

Mate choice and cannibalism in a natural population of a stream goby,Rhinogobius sp.

Breeding ecology of the stream goby,Rhinogobius sp. LD (Large Dark), was investigated under natural conditions. Males selectively courted females of similar size to lead them to the nests, whereas females followed courting males preferentially when the relative male size was greater. Male-male competition for a female was relatively infrequent and not severe. Developmental stages of eggs and egg numbers in one nest indicated that males receive 1–3 clutches during one breeding cycle. Males guarding multiple clutches frequently ate some of the eggs, but those guarding single clutches rarely did so. Gravid females in the nest also frequently cannibalized eggs laid by a previous female, probably in order to extend the area available for egg deposition. Mate choice in this species is discussed in relation to paternal ability, limitation of available spawning area and the female-biased sex ratio.