Circadian Structural Changes in the Retina of Lycosa tarentula (Araneae: Lycosidae)

Daily structural changes of the rhabdoms are described in the four eye types of a lycosid spider submitted to laboratory conditions: LD 12:12 (light on at 08.00, 100 lux). From a study of animals submitted to constant darkness during fourteen days, rhabdom turnover was shown to be circadian. Each type of retina exhibits its own rhythmic turnover of rhabdoms. Anterior-lateral, posterior-median and lateral eyes are mostly diurnal; anterior-median retinae comprise 300 receptors with mainly nocturnal functioning and 150 receptors with mainly diurnal functioning. A correlation was found between rhythms of locomotor activity, other activity, and rhabdom turnover in L. tarentula suggesting that the same pacemaker controls these different rhythms.     

Circadian Structural Changes in the Retina of Lycosa tarentula (Araneae: Lycosidae)

Daily structural changes of the rhabdoms are described in the four eye types of a lycosid spider submitted to laboratory conditions: LD 12:12 (light on at 08.00, 100 lux). From a study of animals submitted to constant darkness during fourteen days, rhabdom turnover was shown to be circadian. Each type of retina exhibits its own rhythmic turnover of rhabdoms. Anterior-lateral, posterior-median and lateral eyes are mostly diurnal; anterior-median retinae comprise 300 receptors with mainly nocturnal functioning and 150 receptors with mainly diurnal functioning. A correlation was found between rhythms of locomotor activity, other activity, and rhabdom turnover in L. tarentula suggesting that the same pacemaker controls these different rhythms.     

Circadian rhythms of melatonin in haemolymph and optic lobes of Chinese mitten crab (Eriocheir sinensis) and Chinese grass shrimp (Palaemonetes sinensis)

This study is the first to examine the circadian rhythms of melatonin in Eriocheir sinensis and Palaemonetes sinensis, two economically important crustaceans. We collected haemolymph and optic lobes from both species every 4 h over a whole day cycle. Melatonin content was measured with high-performance liquid chromatography. E. sinensis haemolymph exhibited significant (p < 0.05) peaks in melatonin at 16:00 (0.180 ± 0.020 μg·mL^?1) and 24:00 (0.244 ± 0.055 μg·mL^?1), while eyestalks had significant peaks at 16:00 (72.377 ± 18.100 μg·eyestalk^?1) and 24:00 (98.756 ± 30.271 μg·eyestalk^?1). In P. sinensis, melatonin peaked significantly only at 16:00 in optic lobes (12.493 ± 1.475 μg·eyestalk^?1) (p < 0.05); no significant peaks were present in haemolymph. Thus, both E. sinensis and P. sinensis exhibit species-specific melatonin rhythms. Time of day should therefore be considered when examining the physiological status of both crustaceans, given the potential influence of fluctuating daily melatonin concentrations.     

Circadian Rhythms of Locomotor Activity in Lycosa tarentula (Araneae, Lycosidae) and the Pathways of Ocular Entrainment

Lycosa tarentula is a ground-living spider that inhabits a burrow where it awaits the appearance of prey or conspecifics. In this study, circadian rhythms of locomotor activity were examined as well as the ocular pathway of entrainment. Thirty-three adult virgin females were examined under constant darkness (DD); all of them exhibited robust circadian rhythms of locomotor activity with a period averaging 24.1h. Fourteen of these spiders were studied afterwards under an LD 12:12 cycle; they usually entrained to in the first or second day, even when the light intensity was as low as 1 lx. During the LD cycle, locomotor activity was generally restrained to the darkness phase, although several animals showed a small amount of diurnal activity. Ten males were also examined under LD; they were also nocturnal, but were much more active than the females. Seven females were examined under constant light (LL); under this they became arrhythmic. Except for the anterior median eyes (OMAs), all the eyes were capable of entraining the locomotor activity to an LD cycle. These results demonstrate that under laboratory conditions and low light intensities locomotor activity of Lycosa tarentula is circadian and in accordance with Aschoff's 'rule'. Only OMAs are unable to entrain the rhythm; the possible localization of circadian clock is therefore discussed.     

Circadian Rhythms of Locomotor Activity in Lycosa tarentula (Araneae,Lycosidae) and the Pathways of Ocular Entrainment

Lycosa tarentula is a ground-living spider that inhabits a burrow where it awaits the appearance of prey or conspecifics. In this study, circadian rhythms of locomotor activity were examined as well as the ocular pathway of entrainment. Thirty-three adult virgin females were examined under constant darkness (DD); all of them exhibited robust circadian rhythms of locomotor activity with a period averaging 24.1h. Fourteen of these spiders were studied afterwards under an LD 12:12 cycle; they usually entrained to in the first or second day, even when the light intensity was as low as 1 lx. During the LD cycle, locomotor activity was generally restrained to the darkness phase, although several animals showed a small amount of diurnal activity. Ten males were also examined under LD; they were also nocturnal, but were much more active than the females. Seven females were examined under constant light (LL); under this they became arrhythmic. Except for the anterior median eyes (OMAs), all the eyes were capable of entraining the locomotor activity to an LD cycle. These results demonstrate that under laboratory conditions and low light intensities locomotor activity of Lycosa tarentula is circadian and in accordance with Aschoff's 'rule'. Only OMAs are unable to entrain the rhythm; the possible localization of circadian clock is therefore discussed.     

A revision of the genus Trabaea Simon (Araneae: Lycosidae)

The genus Trabaea Simon is revised. Nine species are included in the genus of which two are described as new. Trabaeosa straeleni Roewer is newly synonymised with Trabaea purcelli Roewer. A key to the species of Trabaea is provided and the relationships of the genus are discussed.     

Raveniola niedermeyeri from Iran: redescription and new data on distribution (Araneae, Nemesiidae)

Raveniola niedermeyeri (Brignoli, 1972), a poorly known species, is rediagnosed and redescribed from the types and from recently collected material from northern and central regions of Iran. This species differs from its congeners in having the male embolus curved distally, as well as in the unique conformation of the spermathecae. New data on the distribution of Raveniola niedermeyeri in Iran are also provided.     

Age and Sex-Based Differences in the Use of Prey Sensory Cues in Wolf Spiders (Araneae: Lycosidae)

Differences in foraging patterns mediated by sensory cues were examined between adult and juvenile male and female wolf spiders (Schizocosa rovneri; Lycosidae). Patch residence time for thirty-one spiders were tested among juveniles and adults in artificial foraging patches. Patches varied in sensory information provided by live prey (crickets) as follows: visual stimuli alone; vibratory stimuli alone; visual and vibratory stimuli together; and control (no stimuli). Spiders moved between patches for one hour, but could not feed. Adult Schizocosa rovneri use primarily visual information to determine patch residence time, but juveniles use vibratory cues as well. Significant age and sex-based differences in the use of sensory cues suggest that observed divergent foraging strategies are partly due to the use of different perceptual cues in prey detection.     

The effect of prey movement on attack behavior and patch residence decision rules of wolf spiders (Araneae: Lycosidae)

We used a video imaging technique to test the effects of prey movement on attack behavior and foraging patch residence time decision rules of wolf spiders. TwelveSchizocosa ocreata (Hentz) (Lycosidae) were tested in an artificial foraging patch stimulus chamber consisting of a microscreen television displaying a computer digitized, animated image of a cricket. Four prey movement treatments were used: (1) a blank screen, (2) a stationary cricket control, (3) a cricket moving for 1 min, and (4) a cricket moving for 10 min. Spiders stayed significantly longer in treatments with higher cricket activity. Spiders also stayed longer when they attacked the stimulus than when they did not. The distribution of patch residence times of spiders indicates a decision rule based on a fixed probability of leaving.     

A self-paced brain interface system that uses movement related potentials and changes in the power of brain rhythms

Movement execution results in the simultaneous generation of movement-related potentials (MRP) as well as changes in the power of Mu and Beta rhythms. This paper proposes a new self-paced multi-channel BI that combines features extracted from MRPs and from changes in the power of Mu and Beta rhythms. We developed a new algorithm to classify the high-dimensional feature space. It uses a two-stage multiple-classifier system (MCS). First, an MCS classifies each neurological phenomenon separately using the information extracted from specific EEG channels (EEG channels are selected by a genetic algorithm). In the second stage, another MCS combines the outputs of MCSs developed in the first stage. Analysis of the data of four able-bodied subjects shows the superior performance of the proposed algorithm compared with a scheme where the features were all combined in a single feature vector and then classified.     

Fitness costs and benefits of antipredator behavior mediated by chemotactile cues in the wolf spider Pardosa milvina (Araneae: Lycosidae)

Animals may exhibit a variety of defensive behaviors in thepresence of indirect predator cues. Such behavior offers immediatefitness benefits but may also incur substantial foraging andreproductive costs. We measured shifts in space use (verticalclimbing) by the wolf spider Pardosa milvina induced by chemotactilecues (silk and excreta) from a co-occurring predatory wolfspider Hogna helluo. We then measured foraging and reproductive costs, as well as survival benefits, of this behavior. For 2weeks, we maintained mated adult female Pardosa in plasticcontainers with one of three treated peat moss substrates:a container previously occupied by a conspecific for 3 days,a container previously occupied by an adult Hogna for 3 days,and a container devoid of either cue (control). We measuredprey capture efficiency, body condition, egg sac production,egg sac weight, and egg number for individuals in each treatment.We also counted the number of Pardosa that survived and exhibitedclimbing behavior in the presence of a live Hogna with andwithout silk and excreta cues. Pardosa climbed container wallssignificantly more often in the presence of Hogna silk andexcreta relative to other treatments. Pardosa exposed to Hognacues coupled with live Hogna survived significantly longerthan spiders that had no predator cues available. Pardosa placedin containers with Hogna cues, but no Hogna, lost weight morequickly, ate fewer prey, were in poorer body condition, producedlighter egg sacs, and produced fewer eggs than spiders in controlor conspecific treatments.     

Neurosecretory cells in the optic lobe of two aquatic coleopteran species,Dineutes indicus aube and Cybister rugulosus redt

In each optic lobe and optic peduncle of two aquatic beetles viz. Dineutes indicus and Cybister rugulosus the neurosecretory cells are observed with the help of various histochemical techniques. These cells are arranged to form a discrete group. A group in the optic lobe of both species contains about 25 to 30 neurosecretory cells. On the basis of staining properties the neurosecretory cells are classified into A and B types. These cells stain with chrome haematoxylin-phloxine and paraldehyde fuchsin, but do not stain with azan. Histochemically, the neurosecretory material is positive for proteins and shows a negative reaction for 1,2-glycols. The cells show variations in RNA contents in correlation with the state of secretory activity. Axons of the neurosecretory cell group of the optic lobe are observed directed to the optic peduncle. The axonal tract from neurosecretory cells in the optic peduncle runs towards the lateral margin of the brain.     

中国转刺蛛属的修订(蜘蛛目:园蛛科)

对中国转刺蛛属Eriophora进行了修订,共记述8种,其中含3个新组合：宝天曼转刺蛛Eriophora baotianmanensis（Hu,Wang＆Wang,1991）和喜马拉稚转刺蛛Ehimalayaensis（Tikader,1975）从园蛛属Araneus移人,杂斑转刺蛛E．poecila（Zhu＆Wang,1994）从扇蛛属历肛n移人;3个新异名：王氏转刺蛛E.wangi Zhu et Song,1994和陕西转刺蛛E.shaanxiensis Zhu et Wang,1994均为宝天曼转刺蛛Ebaotianmanensis（Hu．Wang＆Wang,1991）的异名,松林园蛛A．pineus Yin et a1．,1990为萨哈林转刺蛛E.sachalinensis（Saito．1934）的异名。     

Determinants of Mating Frequency in the Spiny Orbweaving Spider,Micrathena gracilis (Araneae: Araneidae)

Male Micrathena gracilis require two copulations, separated by a dismount, in order to inseminate both reproductive tracts of the female. We examined several factors that might influence a male's copulatory success. Web structure influenced male courtship and dismount tactics, but not copulatory frequency. The presence of another male reduced the likelihood of a given male copulating with both tracts, a limitation mediated by sexual responsiveness of the female. Mating status of the female did influence copulatory frequency; males were less likely to copulate a second time with nonvirgin females. In summary, males modify mating activities to reduce predation by females, to reduce intermale competition, and to avoid expending gametes when there is little chance of fertilization. Females influence males by predatory activities, mediated through web structure, and enhancing sperm competition among males.     

中国巨蟹蛛属（蜘蛛目：巨蟹蛛科）一新种

本文描述了产于云南省的巨蟹蛛科一新种：双球巨蟹珠,Ｈｅｔｅｒｏｐｏｄａ ｂｉｂｕｌｂａ ｓｐ．ｎｏｖ．。本文量度单位：ｍｍ。模式标本保存在湖南师范大学生命科学学院。     

苍白拟幽灵蛛记述(蜘蛛目:幽灵蛛科)

描述苍白拟幽灵蛛Smeringopus pullidus (Blackwall,1858)雄蛛。     

中国狡蛛属1新种记述(蜘蛛目:盗蛛科)

本文记述中国狡蛛属1新种,命名为掌形狡蛛Dolomedes palmatus sp.nov..模式标本保存在河北大学博物馆和广西大学农学院.文中测量单位为mm.     

Ultrastructure of cardiac muscle of Trochosa terricola Thor., Pardosa amentata Clerck,P. pullata Clerck,and Pisaura mirabilis Clerck (Araneae: Lycosidae,Pisauridae)

Summary The ultrastructure of the cardiac muscle in some araneae has been investigated. The sarcolemma invaginates at the Z band and may extend into the cells through several myofibrils. Numerous T-tubules are given off both from sarcolemmal invaginations and also directly from the cell surface. In passing through the Z band, the luminal diameter of T-tubules greatly increases. Dyadic and a few triadic couplings are found mainly at the A-I level. Peripheral couplings were not seen.The ruthenium red solutions employed were prepared as described by Myklebust (1975), but the fixative contained 2% sucrose. The hearts were fixed for 3 1/2h in the ice cold solution, washed in buffer and post-fixed for 1 1/2h in a ruthenium red/OsO₄ solution. Dehydration and embedding was performed as described above. Sections were cut on a Reichert Om U2 microtome, stained with lead citrate (Reynolds, 1963) and examined in a Philips 300 electron microscope at 80 kV.Semithin sections for light microscopy were stained with toluidine blue (Mercer and Birbeck, 1972).I am much obliged to cand. real Erling Hauge for identifying the specimens used in the investigation proportion of relaxed sarcomeres. The fixed pieces were washed in a buffered sucrose solution and post-fixed in a 1% OsO₄ solution buffered with sodium cacodylate for 1 h. Following washes in a compatible buffer and in distilled water, the tissue was stained en bloc for l h in a 2% aqueous uranyl acetate solution. The tissue was dehydrated through cold acetone and embedded in Epon 812.     

Circadian and ultradian (12 h) rhythms of hepatic thiosulfate sulfurtransferase (rhodanese) activity in mice during the first two months of life

Thiosulfate sulfurtransferase (TST) is an important 'enzyme of protection,' that accelerates the detoxification of cyanide, converting it into thiocyanate. The TST physiological rhythm was investigated at wks 2, 4, and 8 of post-natal development (PND) in the mouse. The results revealed a statistically significant gender-related difference, with the highest activity in females, at all the documented PND stages. In the second week of PND (pre-weaning time), the circadian rhythm of the enzyme activity was associated with ultradian components. The prominent circadian rhythm (τ=24 h) peaked at the beginning of the light span, more precisely ∼3 HALO (Hours After Light Onset). A week after weaning (wk 4 of PND), an impairment of the rhythm, with the peak shifted toward the second half of photophase, was recorded. Four to 6 wks later, about wk 8 of PND, the circadian rhythm pattern was stabilized, with its peak then located at the beginning of the dark span (13 HALO). The obtained results showed a 12 h phase-shift of the circadian TST peak time during PND, suggesting that the rhythm stabilization is age-dependent.     

中国伪遁蛛属Pseudopoda 2新种记述（蜘蛛目：异足蛛科）

报道了采白云南的伪遁蛛属Pseudopoda蜘蛛2新种：镇康伪遁蛛,新种Pseudopoda zhenkangensis sp．nov．和蝶形伪遁蛛,新种Prhopalocera sp．nov．．模式标本保存于大理学院生命科学与化学学院和中国林业科学研究院资源昆虫研究所。文中测量单位为mm。