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1.
Early life stages of Artedidraco skottsbergi and A. shackletoni were collected off Adélie Land. The morphology and pigmentation pattern of nine larvae and juveniles of A. skottsbergi between 17.2 and 21.4 mm in standard length (SL), and of two juveniles of A. shackletoni measuring 25.1 mm SL were described. A. skottsbergi was characterized by a heavily pigmented body, except for the caudal peduncle, with distinctively dense pigmentation on the
ventrolateral half of the body and caudal section (17.2–17.9 mm SL). Furthermore, they had no pigmentation on the pectoral
fin base until they attained 21.4 mm SL. Juvenile A. shackletoni had a heavily pigmented body except for the ventral side of the abdomen and the anal fin base. The proximal part of the dorsal
fin and most of the anal fin were covered with melanophores. Although knowledge of larval and juvenile Artedidraco species is limited, the distribution of melanophores on the fins, pectoral fin base and caudal peduncle at each developmental
stage may be useful for species identification. 相似文献
2.
Shiro Nakao 《Applied Entomology and Zoology》2011,46(1):111-116
To determine the level of inter-population variation in wing form and the induction of reproductive diapause as affected by
photoperiod, females of five populations of arrhenotokous Thrips nigropilosus Uzel were reared under four different photoperiodic conditions at 18°C. The experimental populations originated from Nakijin-son,
Motobu-cho, and Uruma-shi in Okinawa Island, Amami-shi in Amami-Oshima Island, and Wakayama-shi on Honshu Island. In all five
populations, only macropterae were observed when the photoperiod was 13 h light/11 h dark. Brachypterae were observed as the
light period was reduced to 11.5 or 12 h in the Wakayama population, and to 10 or 11.5 h in the Nakijin, Motobu, and Uruma
populations. Brachypterous females were observed in the Amami population only when the light period was 10 h. With the same
photoperiod, only brachypterae were observed in the Wakayama and Uruma populations. Short-day conditions also induced reproductive
diapause in the Wakayama population but not in the Amami and Okinawa Island populations. Under 10 h light/14 h dark, almost
all hybrids obtained from crossing Wakayama with Amami populations entered reproductive diapause. Some populations in Okinawa
Island may have been originated in northern localities. 相似文献
3.
Pseudacanthotermes spiniger and P. militaris are two African fungus-growing termites (Termitidae, Macrotermitinae) which may become pests in disturbed agrosystems where
they often live in sympatry. To study their development and their reproductive strategies, colonies of both species were reared
in the laboratory for 20 and 17 years, respectively, after their foundation from reproductive pairs. The first steps of development
were in great part similar in both species, although P. spiniger favoured the defence during the juvenile period, while P. militaris tended to favour a rapid development. While P. spiniger colonies did not produce alates until year 7 of colony life, P. militaris colonies were able to produce a fertile progeny 4 years after their foundation. In contrast, major soldiers were more rapidly
differentiated in the incipient colonies of P. spiniger. Dispersal flights occurred every year for 10 years in P. spiniger. In P. militaris, dispersal flights did not occur regularly although alates appeared yearly. The annual number of alates produced by P. spiniger increased with the colony age to reach a maximum of 25,000 individuals and global production of alates was estimated at ca.
150,000 individuals in the life of a colony. The longevity of P. spiniger and P. militaris colonies was around 20 years. These species were shown to be reproductively isolated by multiple pre-mating mechanisms. While
chronological differences in dispersal flights contribute to reproductive isolation of the two species, the non-viability
of experimental hybrid colonies also indicates the involvement of post-mating mechanisms of isolation. 相似文献
4.
We investigated the breeding season and size at maturation and described the morphology of newly released Hippichthys spicifer larvae collected from the estuaries of four rivers on northern Okinawa-jima Island, southern Japan. The minimum size of brooding
males was 108 mm standard length (SL). The smallest mature female, as estimated from gonadosomatic index (GSI) analysis and
histological observations of gonads, was about 100 mm SL. Histological observations showed the gonad of H. spicifer to be a cylindrical tube with a sequential pattern of follicle development and a single germinal ridge. We surmised that
the breeding season is year-round, as shown by monthly changes in female GSI, gonad histology, and monthly changes in the
occurrence of brooding males. The monthly changes in female GSI and proportions of brooding males were small in winter. The
number of eggs in the male brood pouch ranged from 114 to 1,764 (604.4 ± 322.8, mean ± standard deviation; n = 25). The SL of the released larvae was 9.9 mm. All fins except the pectoral fins were formed, the body was elongated, and
the developmental stage was similar to that of other Urophori species. The smallest individual present in the mangrove areas
of estuaries was 78.0 mm SL. 相似文献
5.
We investigated the size at maturation, breeding season, and morphological development of larvae and juveniles of a freshwater
pipefish Microphis leiaspis, which belongs to Gastrophori, collected from three rivers on the northern part of Okinawa-jima Island, Japan. The minimum
size of brooding males was 105–123 mm in standard length (SL). The smallest mature female was estimated to be ca. 130 mm SL
from the analysis of gonadosomatic index (GSI) and histological observations of gonads. The breeding season was estimated
to be from June to December according to monthly changes in female GSI, histological observations of gonads, and monthly changes
in the occurrence of brooding males. The number of eggs in the male brood pouch ranged from 75 to 241 (mean ± SD: 152 ± 52,
n = 22). The male releases newly hatched larvae in freshwater areas. After newborns grow in the sea, they return to freshwater
areas of the rivers and attain maturity. Microphis leiaspis was conformed to have an amphidromous life history. Notochord length of the released larvae was 6.1 mm, with a well-developed
finfold. Larvae attained 11.1 mm SL, formation of the caudal and dorsal fin rays was complete, and the caudal fin became lozenge
shaped at 30 days after the release, and juveniles reached 36.0 mm SL at 63 days after release. In the period between 30 and
63 days after the release, formation of all fins except the pectoral fins was completed, and caudal fin rays were extended
and sector shaped with deep slits between each fin ray. The morphology of the released larvae of M. leiaspis is similar to that of Gastrophori species, and the morphology of juveniles similar to other species of Microphis. 相似文献
6.
Life history parameters associated with reproductive biology, age, and growth of the convict cichlid (also known as the zebra
cichlid) Amatitlania nigrofasciata, which was introduced into the Haebaru Reservoir on Okinawa-jima Island, were estimated using 437 specimens that ranged from
13.7 to 82.9 mm standard length (SL). Lengths of females at first maturity (SL) and 50% maturity (L
50) were estimated to be 32.2 and 37.3 mm SL, respectively. The spawning period continued throughout the year, with a peak spawning
cycle from March to May 2006–2007. Observations of postovulatory follicles and tertiary yolk stage oocytes indicate that convict
cichlids spawn multiple times within a year. Female cichlids that hatched during the peak spawning seasons matured after October
of the same year. Batch fecundity of females (32.2–61.2 mm SL) ranged from 65 to 345 (mean ± SD = 155 ± 63). Opaque zones
along the outer margins of otoliths formed annually. The maximum age of male and female cichlids was 3 years. The von Bertalanffy
growth formulae (VBGF) were expressed as Lt = 57.4( 1 - e - 0.78( t + 0.91 ) ) {{\hbox{L}}_{\rm{t}}}{ = 57}{.4}\left( {1 - {e^{ - 0.78\left( {t + 0.91} \right)}}} \right) for females and Lt = 69.5( 1 - e - 1.07( t + 0.24 ) ) {{\hbox{L}}_{\rm{t}}}{ = 69}{.5}\left( {1 - {e^{ - 1.07\left( {t + 0.24} \right)}}} \right) for males. Males grew larger than females beginning from the first year. Certain life history characteristics, such as year-round
spawning and early maturation, probably contributed to the successful establishment of the convict cichlid, and this species
in particular is thought to adapt and become established quickly upon introduction to freshwater systems on Okinawa-jima Island. 相似文献
7.
8.
The wild species Brassica
maurorum Durieu (MM, 2n = 16) is useful for the improvement of Brassica crops. Herein, interspecific reciprocal crosses between B. maurorum and three cultivated Brassica allotetraploids were carried out with the aid of embryo rescue. Trigenomic hybrids with Brassica
napus (AACC, 2n = 38) and Brassica
carinata (BBCC, 2n = 34) were produced from reciprocal crosses, but the hybrids with Brassica
juncea (AABB, 2n = 36) were obtained only when B. maurorum was used as female. All the hybrids were morphologically intermediate between their parents, and were male and female sterile.
By in vitro chromosome doubling of the trigenomic hybrids, the allohexaploids (AACC.MM/MM.AACC, 2n = 54; BBCC.MM, 2n = 50; MM.AABB, 2n = 52) were established and characterized for their phenotype and cytology. The fertilities of three allohexaploids were different,
for AACC.MM and MM.AACC failed to produce seeds by selfing, but BBCC.MM showed low seed-set and MM.AABB had good seed-set.
They also expressed variable extents of male meiotic regularity as to chromosome pairing and segregation, with MM.AABB > BBCC.MM > AACC.MM/MM.AACC,
the same order as their fertility. So their meiotic behavior contributed to the fertility. Finally, the potential of these
allohexaploids as a bridge for genetic improvement of Brassica crops was discussed. 相似文献
9.
This paper discusses a number of experiments performed, involving the fusion by an electric field of mesophyll protoplasts
from Solanum tuberosum cv. Bintje, S. tuberosum dihaploid clones 243, 299 and the wild tuberous disease-resistant species S. bulbocastanum and S. pinnatisectum. Three fusion experiments (S. bulbocastanum + S. tuberosum dihaploid 243, S. pinnatisectum + S. tuberosum cv. Bintje and S. pinnatisectum + S. tuberosum dihaploid 299) yielded 542 calli, the 52 ones of which produced shoots. Obtained regenerants were estimated by the flow-cytometry (FC)
and RAPD analysis to determine hybrid plants.The utilisation of the FC as a useful method for detecting somatic hybrids is
also discussed in this paper. The combination S. bulbocastanum + S. tuberosum dihaploid 243 led to the creation of eight somatic hybrids, the combination S. pinnatisectum + S. tuberosum cv. Bintje yielded four somatic hybrids and the combination S. pinnatisectum + S. tuberosum dihaploid 299 resulted in no hybrid regenerants. Morphology in vitro, growth vigour and production of tuber-like structures
were evaluated in hybrid plants. Plants were transferred in vivo for further estimation (acclimatization, habitus evaluation
and tuberization ability). 相似文献
10.
Ken Maeda Nozomi Yamasaki Masashi Kondo Katsunori Tachihara 《Ichthyological Research》2008,55(2):162-174
Larvae and juveniles of six species of Luciogobius were collected at Aritsu Beach on Okinawa Island using a small seine. Postflexion larvae were dominant during sampling and
were collected when they approached the shoreline adjacent to or at the entrances to their adult habitats prior to settlement.
Standard lengths of postflexion larvae ranged from 5.4 to 14.4 mm and varied depending on the species. The larvae occurred
mainly from January to April, but some larvae were caught in October and November. Their pelagic larval durations were estimated
to range from 17 to 36 days and varied depending on the species. Morphologies of field-caught larvae and juveniles and laboratory-reared
juveniles were described. Six species were clearly distinguished based on fin ray and vertebral counts, proportions, body
size, and pigment patterns. Although their taxonomic statuses could not be determined, it is thought that they have independent
relatives in other regions. 相似文献
11.
Atsushi Nanami 《Ichthyological Research》2011,58(4):310-314
The ornate jobfish Pristipomoides argyrogrammicus is an important lutjanid species for fisheries in the Okinawan region of Japan. The present study estimated the size composition
and reproduction of this species in the waters around Ishigaki Island, Okinawa Prefecture. The length–frequency distribution
indicated that males grow larger than females. The fork length (FL; mm)–whole body weight (BW; g) relationship and FL–total
length (TL) relationship were as follows: BW = 1.048 × 10−5 FL3.121 and TL = 1.101 × FL + 2.196, respectively. The main spawning season was estimated as between April and August, since higher
gonadosomatic index (GSI) values were found for both sexes, and matured oocytes were observed in females during these months.
The developmental stage of ovaries correlated with the GSI of females. Fecundity ranged from 9,530 to 98,260 oocytes in fish
of 177.0 to 278.0 mm FL, and the FL–fecundity relationship was as follows: fecundity = 9.525 × 10−8 FL4.903. 相似文献
12.
13.
Post-pollination hybridization barriers in <Emphasis Type="Italic">Nicotiana</Emphasis> section <Emphasis Type="Italic">Alatae</Emphasis> 总被引:1,自引:1,他引:0
Christopher B. Lee Lawrence E. Page Bruce A. McClure Timothy P. Holtsford 《Sexual plant reproduction》2008,21(3):183-195
Nicotiana section Alatae contains eight species with variable flower sizes and morphologies. Section members readily hybridize in the glasshouse,
but no hybrids have been observed in natural sympatric and parapatric populations. To investigate interspecific crossing relationships
with respect to mechanisms preventing hybridization, all members of section Alatae were intercrossed in a complete diallel. We found positive correlation between the pistil length of the pollen donor and
interspecific seed set relative to the conspecific cross. Pollen tube growth rate and pollen donor pistil length were positively
correlated as well. Furthermore, pollen from short-pistil members of section Alatae could only grow a maximum distance proportional to, but greater than, their own pistil lengths. Our results show that pollen
tube growth capacity (i.e., rate and distance), provides a hybridization barrier in long-pistil species × short-pistil species
crosses. We also found another hybridization barrier not specifically related to pollen tube growth capacity in short-pistil
species × long-pistil species. Taken together, these barriers can generally be described by a ‘pistil-length mismatch’ rule;
in section Alatae, pollen has the most success fertilizing ovules from species with pistil lengths similar to their own. This rule could contribute
to hybridization barriers in Section Alatae because the species display dramatically different pistil lengths.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
14.
The growth and survival of larvae can be significantly enhanced through close association with patches of high prey concentration.
However, the taxis and kinesis responses used by larvae to locate and maintain residence in micro-patches remains poorly understood.
In this study, the behavioral responses of Pacific cod (Gadus macrocephalus) and walleye pollock (Theragra chalcogramma) larvae (45–100 dph) to light, prey scent, and prey were examined. Both species displayed an ontogenetic shift in response
to a horizontal light gradient, with small larvae (11–13 mm SL) exhibiting a positive phototaxis and large larvae (23–32 mm
SL) exhibiting a negative phototaxis. Whether this reversal is related to ontogenetically appropriate foraging cues or some
other aspect of the environment remains to be determined. Neither species displayed significant behavioral responsiveness
to the introduction of olfactory prey cues at either size. The aggregating (taxis) response of large larvae to introduction
of live prey was stronger than that of small larvae, possibly due to increased reaction distances and encounter rates. In
addition, both species exhibited a kinesis response of reducing the frequency of swimming bouts in response to introduction
of live prey. These results suggest that the scale of prey patchiness and the physical factors that determine patch encounter
rates are a significant determinant of larval growth and survival in the early feeding stages of marine fishes. 相似文献
15.
Makoto Okamoto 《Ichthyological Research》2011,58(2):101-108
A new epigonid fish, Epigonus mayeri, is described on the basis of two specimens (109.7–113.8 mm in standard length: SL) from off Angola, and Epigonus heracleus Parin and Abramov 1986 is redescribed on the basis of 12 additional specimens with type specimens from off eastern New Zealand.
These species belong to a subgroup of Epigonus, known as the “Epigonus robustus group,” which have a pungent opercular spine and VII-I, 9 dorsal-fin rays. The new species differs from other species of
the group by having a sharp-pointed mustache-like process, presence of a rib on the last abdominal vertebra, vertebrae 10 + 15,
tongue toothless, pyloric caeca 5, pectoral fin reaching to vertical line from anus (length 22.2–23.6% SL), orbital diameter
16.4–17.0% SL, head length 37.8–38.0% SL, and lower jaw length 16.7–17.0% SL. 相似文献
16.
Yoko Yatabe Chie Tsutsumi Yumiko Hirayama Keigo Mori Noriaki Murakami Masahiro Kato 《Journal of plant research》2009,122(6):585-595
Rheophilous Osmunda lancea often hybridizes with a dryland ally, Osmunda japonica, to produce O. × intermedia, forming zonation in riverbanks and the adjacent dryland along flooding frequency clines. This study examined the genetic
structure of populations consisting of O. × intermedia and the two parental species by analyzing ten nuclear DNA markers [six cleaved amplified polymorphic sequence (CAPS) markers
and three simple sequence repeat (SSR) markers developed from an expressed sequence tag (EST) library, and the sequence of
the glyceraldehyde-3-phosphate dehydrogenase gene GapCp] and chloroplast DNA sequences. The results suggest that the nuclear genes of O. japonica and O. lancea are genetically differentiated despite shared polymorphism in their chloroplast DNA sequences. This discrepancy may be attributable
to natural selection and recent introgression, although it is not evident if introgression occurs between O. japonica and O. lancea in the examined populations. Our findings of putative F2 hybrids in O. × intermedia support its partial reproducibility, and also suggest that formation of later-generation hybrids generates morphological
variation in O. × intermedia. O. lancea plants collected from geographically distant localities were genetically very similar, and it is suggested that O. lancea originated monotopically. 相似文献
17.
Hermes copper butterfly (Lycaena [Hermelycaena] hermes) is a rare species inhabiting the coastal sage scrub adjacent to San Diego, CA USA. Conservation groups and wildlife agencies
recognize this species is threatened by habitat loss due to urbanization and recent wildfires extirpating local populations.
To assess the status of the Hermes copper, we summarize the literature concerning taxonomy, distribution, and ecology, as
well as present original distributional and ecological data. Adults were sampled by presence/absence surveys, Pollard Walks,
and mark-release-recapture. The current distribution is reduced from historic ranges, specifically in extreme southern and
northern San Diego County. Recent wildfires in 2003 and 2007 led to the extirpation of many populations, with only one post-fire
recolonization documented. Adult emergence dates ranged from mid-May to early June, while densities varied from five to nine-fold
among years based on peak abundance and mark-release-recapture estimates, respectively. We observed significantly more males;
most were territorial and exhibit a relatively sedentary behavior. The median dispersal range was 25.8 and 11.3 m, and the
median minimum distance traveled was 34.4 and 17.6 m at Rancho Jamul Ecological Reserve and Hollenbeck Canyon Wildlife Area,
respectively. The longest recorded movement by an individual was 1,132.0 m. Post-fire habitat recovery and the ability to
move across the landscape are essential for the Hermes copper to persist in an increasingly dynamic and fragmented coastal
sage scrub habitat. Therefore, we need to develop a better understanding of habitat requirements and connectivity of populations
for the long-term management and conservation of this species. 相似文献
18.
Munenori Kishida Yu Kanaji Songguang Xie Yoshiro Watanabe Tomohiko Kawamura Reiji Masuda Yoh Yamashita 《Environmental Biology of Fishes》2011,90(3):301-315
Morphometric analyses of marine pelagic fishes have generally been conducted for stock identification rather than for ecomorphological
understanding. Many papers on stock identification of Trachurus japonicus reported polymorphisms in the Japanese Islands waters. However, none of them has found polymorphism in fish less than 100 mm
standard length (SL), despite the environmental differences experienced by juvenile cohorts. The objective of this study was
to detect ecomorphological polymorphism of juvenile T. japonicus (<100 mm SL) in Wakasa Bay, Japan, where multiple juvenile cohorts appear. From analyses of size frequency distributions
and otolith microstructure, five cohorts were recognized in the bay from September 2003 to August 2004. We then compared 17
morphometric characters on body, fin, and otolith morphology, and found cohort-specific and roughly dimorphic pattern (a streamlined
morph and a compressed morph). The dimorphism was markedly observed in 50–70 mm SL, and was regarded as specific to the juvenile
stage by comparison with the senior dimorphisms (≥100 mm SL). Referring to the literatures on functional morphology, the streamlined
morph and the compressed morph were considered to be suitable to body and caudal fin (BCF) periodic propulsion and BCF transient
propulsion, respectively. The juvenile dimorphism was interpreted as adaptive in its developmental environments (i.e., ecomorphological
dimorphism) by relating the functional differences to the inferred ecological differences: the streamlined morph is adaptive
to feed on larval Engraulis japonicus in coastal waters, whereas the compressed morph is adaptive to associate with jellyfishes in offshore waters. 相似文献
19.
Jørgen G. Nielsen 《Ichthyological Research》2007,54(4):374-379
A new species of the fish genus Grammonus (Ophidiiformes: Bythitidae) is described based on a ripe female, 98 mm in standard length (SL). It was caught at the bottom
of a cave at a depth of 20 m under lightless conditions in Ie-shima Island, one of the Ryukyu Islands. A comparison to the
seven described species of Grammonus shows the greatest similarity to the widely distributed G. robustus, but G. yunokawai n. sp. differs from it by having fewer vertebrae (41 vs. 44–47), a greater predorsal length (41.5 vs. 32.0–39.0% SL), higher
posterior margin of maxilla (8.4 vs. 5.6–7.3% SL), and greater interorbital width (10.5 vs. 5.9–7.6% SL).
Supplementary material to this paper is available in electronic format at 相似文献
20.
Karin Sonntag Brigitte Ruge-Wehling Peter Wehling 《Plant Cell, Tissue and Organ Culture》2009,96(3):297-305
A method for isolation and shoot regeneration from electrofused protoplasts of L. angustifolius and L. subcarnosus was developed. Viable protoplasts were isolated from leaves of in-vitro grown seedlings at an average yield of 6 × 105 protoplasts g−1 fresh weight. Liquid and agarose solidified B5 media were used for protoplast culture. In the liquid-culture system, all
tested media, VKM, P1 and KM8p, were applicable for inducing cell division (84% of all tested petri dishes at four weeks)
and colony formation. Media containing additional carbohydrates were suitable to produce compact calli with green and brown
pigmentations in different combinations. Analysis of callus with molecular markers allowed to identify six somatic hybrids.
However, none of the parental-protoplast derived cell colonies could develop shoots. This is the first report on protoplast
fusion of L. angustifolius and L. subcarnosus with subsequent shoot regeneration. 相似文献