中国球蛛三新种和二新记录（蜘蛛目：球蛛科）

本文报道了蜘蛛目球蛛科3属3新种和1个中国新记录属2新记录种。新种为笠腹希蛛Achaearanea galeiforma sp.nov.,三斑丽蛛Chryssa trimaculata sp.nov.,奇异球蛛Theridion mirabilis sp.nov.。模式标本保存在河北教育学院生物系。     

Fine Structural Analysis of the Central Nervous System in the Spider, Achaearanea tepidariorum (Theridiidae: Araneae)

ABSTRACT Central nervous system (CNS) of arachnids is still mysterious and has a rich unexplored field compare to what is known in insects or crustaceans. The CNS of the spider, Achaearanea tepidariorum, consists of a dorsal brain or supraesophageal ganglion and circumesophageal connectives joining it to the subesophageal mass. As the segmentation of the arachnid brain is still under discussion, we classify the brain as a protocerebral and tritocerebral ganglion depending on the evidences which generally accepted. The subesophageal nerve mass underneath the brain is the foremost part of the ventral nerve cord. All of this nerve mass is totally fused together, and forming subesophageal ganglia in this spider. In the brain, the nerve cells are packed in the frontal, dorsal and lateral areas, but are not absent from the posterior and ventral regions. In addition, the nerve cells of the subesophageal and abdominal ganglia are only restricted to the ventral and ventolateral regions. The CNS of the spider, Achaearanea tepidariorum is similar in feature to the Family Araneidae.     

Microstructure of the silk apparatus of the comb-footed spider, Achaearanea tepidariorum (Araneae: Theridiidae)

The microstructural organization of the silk‐spinning apparatus of the comb‐footed spider, Achaearanea tepidariorum, was observed by using a field emission scanning electron microscope. The silk glands of the spider were classified into six groups: ampullate, tubuliform, flagelliform, aggregate, aciniform and pyriform glands. Among these, three types of silk glands, the ampullate, pyriform and aciniform glands, occur only in female spiders. One (adult) or two (subadult) pairs of major ampullate glands send secretory ductules to the anterior spinnerets, and another pair of minor ampullate glands supply the median spinnerets. Three pairs of tubuliform glands in female spiders send secretory ductules to the median (one pair) and posterior (two pairs) spinnerets. Furthermore, one pair of flagelliform glands and two pairs of aggregate glands together supply the posterior spinnerets, and form a characteristic spinning structure known as a “triad” spigot. In male spiders, this combined apparatus of the flagelliform and the aggregate spigots for capture thread production is not apparent, instead only a non‐functional remnant of this triad spigot is present. In addition, the aciniform glands send ductules to the median (two pairs) and the posterior spinnerets (12–16 pairs), and the pyriform glands feed silk into the anterior spinnerets (90–100 pairs in females and 45–50 pairs in males).     

Patterns of variation in female-biased colony sex ratios in a social spider

Colonies of a social spider Achaearanea wau (Theridiidae) from Papua, New Guinea have adult and juvenile sex ratios that are biased towards females, and this probably represents a primary bias at the egg stage. Adult sex ratios are less female-biased than are juvenile sex ratios, and both vary significantly among colonies. Adult sex ratios covary with colony size: small colonies have a larger proportion of males than large ones. The pattern of variation in adult sex ratio may be due to greater mortality of females than of males during maturation. Juvenile sex ratios do not covary with colony size, nor do they differ among populations. Colony size, however, does have a significant effect on survival and dispersal in colonies. I conclude, therefore, that a conditional sex ratio strategy, in which the primary sex ratio of the colony is adjusted to changing demographic patterns, does not occur in A. wau. I suggest that environmental heterogeneity acting on individual reproductive output may be responsible for the observed variation among colonies in juvenile sex ratios.     

Immunocytochemical localization of GAD isoforms in the CNS ganglia of the cobweb spider,Achaearanea tepidariorum

Glutamic acid decarboxylase (GAD) is an enzyme that catalyzes the decarboxylation of glutamate to γ‐aminobutyric acid (GABA) and CO₂. It has been discovered that the GAD has a restricted tissue distribution and it is highly expressed in the cytoplasm of GABAergic neurons in the CNS where GABA is used as a neurotransmitter. We have examined the microstructure of ganglionic neurons and nerves arising from the CNS and describe here the immunocytochemical localization of GAD isoforms to reveal the ecophysiological significance of GABA for the web‐building spider's behavior. In the CNS of the cobweb spider, Achaearanea tepidariorum, immunocytochemical localization of GAD isoforms can be detected in the neurons and neuropiles of the optic lobes. In addition, GAD‐like immunoreactive cell bodies are observed at the intrinsic cell bodies near the central body and the symmetric cell clusters of the protocerebrum. However, the fibrous masses within the protocerebral ganglion are not labeled at all. Based on its interconnection with other regions of the CNS, our findings suggest that the central body in the web‐building spider may act as an association center as well as a visual center.     

Responses of an araneophagic assassin bug,Stenolemus bituberus,to spider draglines

Abstract 1. Animals, as they move through their environment, leave traces of their passage that can be informative to others and convey significant advantages to the animal producing them. However, such traces may also reveal presence, location or identity to enemies. 2. We studied an araneophagic (‘spider‐eating’) assassin bug, Stenolemus bituberus (Heteroptera, Reduviidae), testing whether it associated with areas containing chemotactile traces (e.g. draglines, excreta) left behind by nine sympatric spider species. Stenolemus bituberus were presented with a choice between a substrate containing draglines and a clean substrate. Each hour, for a duration of 12 h, we recorded which substrate was occupied. 3. Stenolemus bituberus tended to associate especially with draglines left by spiders from the genus Achaearanea, their most common prey in nature. 4. These results suggest that S. bituberus exploits draglines from these spiders as cues for indicating prey presence. We also found an increasing tendency to associate with draglines from some spider species through the day, which may be related to circadian patterns or slower response times of some individuals.     

温室希蛛染色体的观察(蜘蛛目:球蛛科)

报道了温室希蛛的染色体数目、形态结构和性染色体组成。从目前的结果可见,温室希蛛的染色体数目是:雄性体细胞染色体数为2n=22,雌性为2n=24。其性决定机制属于X_1X_2O型。所有染色体似乎均为端或亚端着丝粒染色体,这个结论被对其C-带标本的分析所证实。两个(对)X-染色体是最短的和次最短的,温室希蛛染色体C-带标本的分析没有观察到染色体间有明显的结构差异。在染色体G-带标本中,获得了稳定的带纹。     

浙江省希蛛属一新种记述：（蜘蛛目：球蛛科）

本文记述在浙江采到的球蛛科希蛛属一新种:钟希蛛Achaearanea campanulata sp.nov.。本新种与A.angulithorax(Boesenberg et Strand)和A.ferrumequnum(Boesenberg et Strand,)两个种近似,它们的巢都似钟形,但外雌器形状有明显的区别。     

Structural analysis of theridiid spider's testicular cyst using 3D reconstruction rendering

A three dimensional reconstruction technique was used for the analysis of a theridiid spider's (Achaearanea tepidariorum) testicular cyst. Although microscopic techniques have greatly improved, most of the information gathered is still based on two‐dimensional images. Particularly in spiders, it is very difficult to count the exact number of sperm in a single cyst, since their spermatogenetic processes takes place within the spherical cysts through the flagellar coiling process. Since morphological features of spider sperm provide detailed information on the whole spermatogenetic processes, we analyzed the exact number of germ cells per cyst in A. tepidariorum through a three‐dimensional image reconstruction technique. For image processing, serially sectioned histological images were scanned using a light microscope and 3D rendering images were reconstructed from these sections. Based on the three dimensional image analysis of the testicular cyst, the number of secondary spermatocytes per cyst was calculated to be 32 (2⁵). Therefore the total number of sperm produced from a single cyst can be calculated as 64 (2⁶), which indicates that a single spermatogonium undergoes four mitotic divisions and an additional two meiotic divisions to produce mature spermatozoa.     

中国球蛛科二新种：（蜘蛛目：球蛛科）

本文记述我国球蛛科二新种,既采自四川省青城山和峨嵋山的二齿丽蛛和安徽省屯溪市的隆首希蛛。