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1.
Sandgrouse (Pterocles spp.) are adapted to extreme desert environments. One such adaptation is that males transport water in their abdominal feathers to water the nesting female and hatchlings. Hence, understanding sandgrouse drinking regime and regularly used water holes is of great conservation importance. We studied the arrival of four sandgrouse species at a single water hole in the western Negev Desert, Israel. During our visits, the most numerous species was the Spotted Sandgrouse, and in decreasing abundance, we found Black-bellied Sandgrouse, Crowned Sandgrouse, and Pin-tailed Sandgrouse. Black-bellied Sandgrouse arrived significantly earlier than Spotted Sandgrouse and Crowned Sandgrouse. Spotted Sandgrouse arrival peaked later in the morning than Black-bellied Sandgrouse and Crowned Sandgrouse. The data suggest that this is connected to the absolute number of birds for each of the species which influences their synchronous arrival. Also, we find that the amount of time a species spends at the water hole is influenced by the number of birds present, i.e., the species that stay the longest are also the most numerous. The mean temperature when Spotted Sandgrouse peaked was marginally higher (21.2°C) than recorded for Black-bellied (19.5°C) and Crowned Sandgrouse (19.3°C).  相似文献   

2.
Six specimens of the Shantar snailfish Liparis schantarensis are found in the Taui Bay region of the Sea of Okhotsk for the first time. The new location is approximately midway between two the previously known areas of habitation of the species. The mature males of Shantar snailfish show two peculiarities which were not noted for the species until now: the essential lengthening of rays of the anterior dorsal fin, and the presence of skin spines on the body.  相似文献   

3.
A specimen of the cubed snailfish, Liparis tessellatus was captured in Peter the Great Bay, Sea of Japan. The capture of L. tessellatus from this area a century after the first record is evidence that at present this species still inhabits Peter the Great Bay.Original Russian Text Copyright © 2005 by Biologiya Morya, Sokolovskii, Sokolovskaya.  相似文献   

4.
Spotted Halibut (Verasper variegatus) is a commercially important marine fish species. In the present study, to isolate sex-specific markers in Spotted Halibut, we screened the genomes of Spotted Halibut by AFLP technique with 64 different primer combinations. Two primer combinations, MseI-CAG/EcoRI-ACC and MseI-CAT/EcoRI-AGG, produced a female-specific fragment in all females (n = 88) and in no males (n = 60, except 3 individuals), respectively. Both fragments were excised from the gel, cloned and characterized. The first fragment (named VevaF533) was 533 bp long, while the length of the second one (named VevaF218) was 218 bp. The two sequences showed no similarity to each other, and to the known sequences existing in the GenBank database using BLASTn. Cross-species amplification showed that the marker VevaF218 is a species-specific marker which is present in Spotted Halibut females but absent in Barfin Flounder (Verasper moseri). So this marker could be used for discriminating unambiguously between Spotted Halibut females and Barfin Flounder. Examination of the patterns of inheritance of VevaF218 in an interspecific hybrid family (V. variegatus ♂×V. moseri ♀) showed a female-specific pattern of inheritance from mother to daughter, implying that the marker VevaF218 is located on the female sex chromosome. This study provides a reliable AFLP-based genetic sexing of Spotted Halibut that could be useful for genetic mapping of the sex chromosomes and identification of sex-linked genes.  相似文献   

5.
The three subspecies of Spotted Owl (Northern, Strix occidentalis caurina; California, S. o. occidentalis; and Mexican, S. o. lucida) are all threatened by habitat loss and range expansion of the Barred Owl (S. varia). An unaddressed threat is whether Barred Owls could be a source of novel strains of disease such as avian malaria (Plasmodium spp.) or other blood parasites potentially harmful for Spotted Owls. Although Barred Owls commonly harbor Plasmodium infections, these parasites have not been documented in the Spotted Owl. We screened 111 Spotted Owls, 44 Barred Owls, and 387 owls of nine other species for haemosporidian parasites (Leucocytozoon, Plasmodium, and Haemoproteus spp.). California Spotted Owls had the greatest number of simultaneous multi-species infections (44%). Additionally, sequencing results revealed that the Northern and California Spotted Owl subspecies together had the highest number of Leucocytozoon parasite lineages (n = 17) and unique lineages (n = 12). This high level of sequence diversity is significant because only one Leucocytozoon species (L. danilewskyi) has been accepted as valid among all owls, suggesting that L. danilewskyi is a cryptic species. Furthermore, a Plasmodium parasite was documented in a Northern Spotted Owl for the first time. West Coast Barred Owls had a lower prevalence of infection (15%) when compared to sympatric Spotted Owls (S. o. caurina 52%, S. o. occidentalis 79%) and Barred Owls from the historic range (61%). Consequently, Barred Owls on the West Coast may have a competitive advantage over the potentially immune compromised Spotted Owls.  相似文献   

6.
Konrad Leniowski  Ewa Węgrzyn 《Ibis》2013,155(4):804-813
Carotenoid‐based plumage ornaments have the potential to signal individual condition and health in many species of birds. However, very little is known about the function of red plumage in woodpeckers. We assessed whether the red cap displayed by both male and female Middle Spotted Woodpeckers reflects individual quality, finding that the size of the cap is sex‐dependent, whereas the brightness of the cap correlates with the body condition of an individual. Furthermore, birds with brighter caps had larger clutches, suggesting that cap coloration may be an honest signal of parental quality in woodpeckers. Interestingly, more colourful individuals also occupied smaller territories, suggesting that territory size and territory quality may be inversely related in the Middle Spotted Woodpecker.  相似文献   

7.
Type I antifreeze proteins (AFPs) are alanine-rich α-helical polypeptides found in some species of right-eye flounders, sculpin, and snailfish. In this study, a shorthorn sculpin skin type I cDNA clone was used to probe an Atlantic snailfish liver cDNA library in order to locate expressed genes corresponding to snailfish plasma AFPs. Clones isolated from the cDNA library had sections with substantial amino acid and nucleotide sequence similarity to snailfish type I AFPs. However, further analysis revealed that the positives were actually three different liver-expressed proteins—two were eggshell proteins, while the third was a type II keratin. We propose that a shift in reading frame could produce alanine-rich candidate AFPs with possible antifreeze activity or ice crystal modification properties. Furthermore, it is plausible that one or more of the liver-expressed proteins represent the progenitors of snailfish type I AFPs. [Reviewing Editor: Dr. John Oakeshott]  相似文献   

8.
根据2009年7—8月、10月和2010年1月、5月黄海中南部渔业生物底拖网调查数据,对该海域细纹狮子鱼的生物学特征及其分布的季节变化作了分析。结果表明,细纹狮子鱼平均体长和平均体重从春季(4.7 cm、3.3 g)到冬季(34.2 cm、764.9 g)呈显著增加,并且雄性个体平均体长显著大于雌性个体(P<0.05,春季除外)。性比(♀∶♂)随体长组和季节变化,体长越大趋向于雄性,反之趋向于雌性;夏季雄鱼居多(0.70∶1,P<0.05),秋季则为雌鱼居多(1.35∶1,P<0.05),而冬季(产卵群体)和春季性比接近于1∶1。细纹狮子鱼各季节摄食等级均在2.5以上,冬季雄性个体摄食等级显著大于雌性个体(P<0.05),但雄性个体肥满度为全年最低(1.52)。细纹狮子鱼相对资源量和贡献率从春季(0.17 kg/h,1.54%)到秋季(15.36 kg/h,33.05%)呈上升状态,而冬季(2.37 kg/h,5.60%)有所下降。相比2000年,夏秋季相对渔获量和贡献率提高明显。全年集中分布于7.8—13.6℃,3.20%—3.38%的水域,平均体重和水深有显著的相关性(秋季除外)。另外,根据性成熟个体分布区和稚幼鱼分布的相关历史资料分析发现,除海州湾外,黄海中部深水区可能是细纹狮子鱼的产卵场。  相似文献   

9.
Laboratory experiments were conducted to assess shelter use and behaviour of juvenile Spotted Wolffish, Anarhichas minor, using time-lapse video. Information about the behaviour of Spotted Wolffish and its habitat utilization is sparse due to the great depth at which this species lives. Four experiments were conducted using one or two fish per tank, with and without a shelter. The positions and movements of fish in the tanks and interactions between fish were monitored over 24-h periods. In experiments in which no shelter was available, Spotted Wolffish spent very little time exploring the water column. They did not show fidelity to a particular area on the bottom of the tank and exhibited few signs of aggressiveness to each other. When a shelter was made available, fish spent most of their time in the shelter or close to the shelter. The presence of a single shelter did not enhance aggressive behaviours in fish kept in pairs. When day and night observations were compared, no clear diel pattern emerged. The Canadian recovery plan for Spotted Wolffish calls for research aimed at describing their use of demersal habitats. The present study suggests that shelter availability might be an important feature of the habitat requirements of juvenile Spotted Wolffish.  相似文献   

10.
Hans Winkler 《Oecologia》1973,12(2):193-208
Summary The Syrian Woodpecker, Picoides syriacus, acquires its food by excavating, probing, gleaning and fly-catching (Fig. 1). The food-acquisition is carried out from ground level to the crown layer of trees and beyond (Fig. 2).In an ecological sense the Syrian Woodpecker occupies an intermediate position between the Great Spotted and the Middle Spotted Woodpecker (Picoides major and medius). That is true for food-acquisition since it excavates more than medius and less than major whilst probing more than major and less than medius. The species is also intermediate in the choise of base from which foraging is done. Great Spotted Woodpeckers are found frequently on thin twigs and Middle Spotted Woodpeckers on thick stems.Between Great Spotted and Syrian Woodpecker there exist interspecific territoriality. Both are neutral with respect to the Middle Spotted Woodpecker. In spite of strong competition for nesting holes and frequent aggression the territories of Syrian Woodpecker and Starling (Sturnus vulgaris) overlap. These findings are discussed.  相似文献   

11.
Russian knapweed ( Acroptilon repens ) and Spotted knapweed ( Centaurea maculosa ) are allelopathic weeds invasive in North American grasslands. Both species contain at least one phytotoxic flavonoid root exudate with demonstrated negative influences on other plants. Previous findings indicated that Silky lupine ( Lupinus sericeus ), among other legumes, was relatively resistant to Spotted knapweed invasion and allelochemistry. We hypothesized that legume species may exhibit resistance to flavonoids in knapweed root exudates and may serve as candidate species for management efforts. Because legumes form symbiotic relationships with rhizobia, these bacteria must also be evaluated for allelochemical resistance before legumes can be recommended for restoration. In this study, we examined four legume species for effects of 7,8-benzoflavone (from Russian knapweed) and (±)-catechin (from Spotted knapweed) on rhizosphere interactions involving legume roots and associated rhizobia. Pure cultures of four rhizobia strains exhibited varied responses when grown with 7,8-benzoflavone or (±)-catechin. Alfalfa ( Medicago sativa ) and its bacterial symbiont, Sinorhizobium meliloti , exhibited allelochemical resistance that varied with (±)-catechin concentration when grown in vitro. Four legume species were grown under greenhouse conditions. Plants that were inoculated and nodulated generally exhibited no response to 7,8-benzoflavone or (±)-catechin treatments. Plants that were not inoculated exhibited stronger responses. Therefore, inoculation and nodulation may confer resistance to allelochemicals. These results, when coupled with previous research and field observations, suggest that legumes may not be susceptible to knapweed allelopathy and may be good choices in restoration of knapweed infestations when inoculated, particularly on sites with low soil nitrogen.  相似文献   

12.
13.
Although the effects of shifting fire regimes on bird populations have been recognized as important to ecology and conservation, the consequences of fire for trophic interactions of avian species – and raptors in particular – remain relatively unknown. Here, we found that within national parks with long‐standing (40+ years) fire management programmes, California Spotted Owls Strix occidentalis occidentalis consumed predominantly Woodrats Neotoma spp. and Pocket Gophers Thomomys spp.; however, in contrast to our predictions, when their territories experienced more extensive and frequent fire, Spotted Owls consumed proportionally more Flying Squirrels Glaucomys oregonensis. We hypothesize this finding could have been driven by either changes to prey abundance following fires (e.g. increases in flying squirrels) or changes to prey availability (e.g. shifts in forest structure or flying squirrel spatial distribution that increased predation upon them by owls). Our work thus demonstrates that fire may have unexpected consequences for the trophic interactions of raptor species and provides valuable information for the conservation of Spotted Owls in fire‐prone forest landscapes.  相似文献   

14.
Paraliparis adustus sp. nov., a snailfish species from the Bering Sea near the Aleutian Island Archipelago, Alaska, is described based on a single mesopelagic specimen. This new species is clearly distinguished by a combination of several morphological features and meristic counts, including long pointed gill rakers with 0–3 spinules at or near the tip, anus positioned forward near the pectoral symphysis, and color uniform brown. Paraliparis bullacephalus sp. nov. from Shelikof Strait, Gulf of Alaska, is also described. This new species is very similar in meristic characters and general body shape and size to P. holomelas Gilbert, but differs primarily in morphological features of the head, particularly in the shape of the dorsal contour of the head, snout, and opercular flap, mouth size, and eye position.  相似文献   

15.
The first articially fertilized spotted wolffish eggs hatched only 10 years ago, and today the species is considered a very promising candidate species for cold water aquaculture in the North Atlantic. Recent research has focused on identifying key biological parameters in spotted wolffish aquaculture in order to establish a full production line for the species, and basic aspects of reproduction and larval development are now understood, controlled, and no longer limiting production. Spotted wolffish eggs (5–6 mm) have a protracted incubation period (800–1000 D°) and newly hatched individuals (20–25 mm) are well developed, with the only larval characteristic remaining being a relatively small yolk sac which is completely resorbed after 3–4 weeks. The species can be weaned directly on formulated feed, and high specific growth rates have been obtained in land-based culture facilities using shallow raceways. Adaptive immune responses are present early after hatching and few potential disease problems have been identified. Only one bacterial disease, atypical furunculosis, has been reported in farmed fish, but oil-emulsified vaccines have displayed efficient protection both in juvenile and adult fish. Ectoparasites may, however, constitute a problem during parts of the year when sea-water temperature increases.Optimal temperature for growth decreases with increasing fish size and is 10–12 °C for early juveniles and 4–6 °C for adult fish and broodstock. Spotted wolffish is a very robust species, and juveniles thrive at high densities and may be reared at a wide range of salinity levels. The species has further displayed a high tolerance to environmental changes in water quality parameters such as oxygen, carbon dioxide and un-ionized ammonia. Currently, the possibility of rearing spotted wolffish in flat-bottom net cages with shelves in the sea is being investigated. Preliminary results suggest that sea-based production may be a viable alternative to land-based rearing of the species in certain areas.  相似文献   

16.
A new species of the family Liparidae, fulvous snailfish Careproctus fulvus sp. n., is described from the Novaya Zemlya Depression of the Kara Sea at a depth between 190 and 414 m. The species belongs to the group of slit-eyed Careproctus (longitudinally oval pupil, elongated lower lobe of the pectoral fin, and large urogenital papilla). The representatives of the species are characterized by fulvous coloration with orange spots, deep body, small teeth, and three radials in the pectoral girdle. The eggs are deposited into glass sponges Schaudinnia rosea (Rossellidae). Valvatophilia (commensalism with bivalves) and carcinophilia (reproductive commensalism with crab-like decapod crustaceans of the family Lithodidae) have been registered in the family Liparidae before, but spongiophilia are described for the first time. Egg deposition into glass sponges (Rossellidae) is known also for cod icefishes (Nototheniidae) from Antarctic waters. Reproductive commensalism between the representatives of the family Liparidae in the Arctic, the species of the family Nototheniidae in the Antarctic, and glass sponges represents a new finding of bionomic bipolarity (independent appearance of similar adaptations in unrelated groups of fishes in two polar regions of the earth). Based on the ecologo-ethological classification of fish reproduction, brood hiding Careproctus species belong to ostracophils, a group of fishes deposited the eggs into live animals.  相似文献   

17.
The conservation of Spotted Owl (Strix occidentalis) populations has been one of the most controversial and visible issues in United States conservation history. Coincident with declines in Spotted Owl populations over the last three decades has been the invasion of Barred Owls (Strix varia) throughout the range of the Northern Spotted Owl (S. o. caurina) and into the range of the California Spotted Owl (S. o. occidentalis). This invasion has confused the reasons behind recent Spotted Owl declines because anecdotal and correlative information strongly suggests that Barred Owls are a new factor influencing the declines. There is great uncertainty about all aspects of the invasion, and this has sparked discussion about appropriate management and research responses regarding the effects of this invasion on Spotted Owls. We present a set of possible responses to address the issue, and we discuss the relative merits of these with regard to their efficacy given the current state of knowledge. We recommend that research specifically aimed at learning more about the interspecific relationships of these two owls throughout the range of sympatry should begin immediately. Approaches that seem unlikely to be useful in the short-term either because they do not facilitate knowledge acquisition, are relatively costly, or would be technically less feasible, should not be considered viable at this time. We believe the consequences of the invasion are potentially dire for the Spotted Owl and that research and management actions, including the use of adaptive management, are required to inform the near- and long-term decision-making process for conservation of Spotted Owls.  相似文献   

18.
19.
The processes of competition and predation determine the degree to which species can coexist; the importance of competition in particular has been emphasized at high trophic levels. Competition exclusion will occur when habitat overlap between sympatric species is high. In this study, we investigated nesting habitat overlap between internationally protected diurnal tree-nesting avian predators of central Europe, namely, White-tailed Eagle (Haliaeetus albicilla), Lesser Spotted Eagle (Aquila pomarina), Black Stork (Ciconia nigra), and Osprey (Pandion haliaetus). We found significantly different nesting habitats among the study species and suggest that this could be a consequence of the resource-based segregation, but not a consequence of asymmetrical interspecific competition. The results also show that habitat of the recovering populations of White-tailed Eagle overlapped with the habitat used by the Lesser Spotted Eagle, Black Stork, and Osprey to varying extents with a niche overlap values being below the competition exclusion threshold. Nevertheless, we suggest that competition by White-tailed Eagle at a population level may limit Osprey, though not Lesser Spotted Eagle or Black Stork.  相似文献   

20.
Summary The snailfish family Liparididae was well represented in bottom trawl hauls (205–370 m) from the Spitsbergen area, with Liparis gibbus being the dominant species. Careproctus reinhardti was less numerous. The present paper is based on 539 specimens of C. gibbus (size range 6–25cm) and 120 specimens of L. reinhardti (size range 5–26 cm). Both species showed a rather similar size and age distribution. The stomach contents reveal that both snailfish species feed both benthically and pelagically. Crustaceans, especially amphipods and decapods, were the most common prey items. With increasing size of the fish, the decapod Pandalus borealis becomes more important, particularly for L. gibbus. Juvenile Liparis (1.3–4.3 cm in length) were found pelagically (35–200 m), and their diet mainly consisted of copepods and young hyperiid amphipods.  相似文献   

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