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Microstructure of the silk spinning nozzles in the lynx spider, Oxyopes licenti (Araneae: Oxyopidae)
Abstract
The lynx spiders are free wandering spiders with long spines on their legs. They do not build web, but hunt small insects on plants. In spite of the facts that the wandering spiders do not produce webs for prey‐catching, they also have silk apparatuses even though the functions are not fully defined. This paper describes the microstructural organization of the silk‐spinning nozzles and its silk glands of the lynx spider, Oxyopes licenti, revealed by the field emission scanning electron microscope (FESEM). The silk‐spinning nozzles of this spider were identified as three groups: ampullate, pyriform and aciniform glands. Each group of silk gland feed silk into one of the three pairs of spinnerets. Two pairs of major ampullate glands send secretory ductules to the anterior spinnerets, and another two pair of minor ampullate glands supply the middle spinnerets. In addition, the pyriform glands feed silk into the anterior spinnerets (25–30 pairs in females and 24–40 pairs in males), and the aciniform glands send ductules to the middle (9–12 pairs in females and 7–11 pairs in males) and the posterior spinnerets (16–20 pairs in females and 16–17 pairs in males). Among these, the ampullate one is the most predominate gland in both sexes. However the flagelliform and the aggregate glands which had the functions of cocoon production or adhesive thread production in other web‐building spiders were not observed at both sexes of this spider.
... 계통학적으로 새거미아목 (Araneomorphae)의 거미들은 체판의 유무에 따라 체판류와 무체판류로 구분되는데, 체판 류의 거미들이 상대적으로 원시적인 분류군으로 추정되고 있다 (Eberhard & Pereira, 1993). 그러나, 체판류와 무체판류 의 거미가 동일한 분류군에 함께 속해 있는 경우도 흔히 발 견되기 때문에 (Lehtinen, 1967), 모든 진정거미류가 원래 체 판을 가지고 있었으나, 진화에 의해 일부 종의 체판이 소실 되었다는 견해가 설득력을 얻고 있는 실정이다 (Coddington & Levy, 1991 (Kovoor, 1987;Nentwig & Heimer, 1987;Peters & Kovoor, 1991;Moon & An, 2006;Moon, 2006Moon, , 2008Moon & Park, 2008 (Peters, 1987;Peters & Kovoor, 1991). 체 판은 원시형의 거미류가 가지고 있던 방적돌기의 한 유형 으로 표면에 수백 또는 수천개의 작은 토사관이 돌출되어 각각의 토사관으로부터 생성된 수백 가닥의 체판 미세사 (fibril)를 한꺼번에 방사하는 특성을 지니고 있다 (Nentwig & Heimer, 1987;Opell 1995Opell , 1999. ...
... 계통학적으로 새거미아목 (Araneomorphae)의 거미들은 체판의 유무에 따라 체판류와 무체판류로 구분되는데, 체판 류의 거미들이 상대적으로 원시적인 분류군으로 추정되고 있다 (Eberhard & Pereira, 1993). 그러나, 체판류와 무체판류 의 거미가 동일한 분류군에 함께 속해 있는 경우도 흔히 발 견되기 때문에 (Lehtinen, 1967), 모든 진정거미류가 원래 체 판을 가지고 있었으나, 진화에 의해 일부 종의 체판이 소실 되었다는 견해가 설득력을 얻고 있는 실정이다 (Coddington & Levy, 1991 (Kovoor, 1987;Nentwig & Heimer, 1987;Peters & Kovoor, 1991;Moon & An, 2006;Moon, 2006Moon, , 2008Moon & Park, 2008 (Peters, 1987;Peters & Kovoor, 1991). 체 판은 원시형의 거미류가 가지고 있던 방적돌기의 한 유형 으로 표면에 수백 또는 수천개의 작은 토사관이 돌출되어 각각의 토사관으로부터 생성된 수백 가닥의 체판 미세사 (fibril)를 한꺼번에 방사하는 특성을 지니고 있다 (Nentwig & Heimer, 1987;Opell 1995Opell , 1999. ...
... 먼저 표면 에서 방사된 체판의 북슬털은 마치 고리 구조를 지닌 벨크 로 접착포의 부드러운 표면처럼 곤충 다리에 있는 강모와 접착하게 되며, 또 한편으로는 반데르발스 인력 (Gorb et al., 2002) 등에 의해 곤충 체표의 큐티클과 접착을 형성하게 되 는 것으로 알려져 있다 (Opell, 1999(Opell, , 2002. 이런 특성으로 인해 체판에서 생성된 미세사가 강모가 많은 파리의 몸체 보다는 매끄러운 구조를 지닌 딱정벌레의 몸통과 좀더 긴 밀하게 접착되었다는 연구결과가 보고된 바 있다 (Hawthorn & Opell, 2002 (Kovoor, 1987)나 늑대거미과(Lycosidae)의 Pardosa astrigera (Moon, 1998), 게거미과의 Misumenops tricuspidatus 와 Oxytate striatipes (Moon & An, 2006), 그리고 스라 소니거미과(Oxyopidae)의 Oxyopes licenti (Moon, 2006 (Kovoor, 1972(Kovoor, , 1984(Kovoor, , 1987 ...
Here we demonstrate the fine structural characteristics of the spigots on the cribellum and its peculiar sieve-like structure at the aspects of the functional significance. The surface of the cribellum is covered by hundred of tiny spigots which producing numerous cribellate silk fibrils. It has been known that the cribellar silk is considered as a quite different sort of catching silk with dry-adhesive properties. By our fine structural observation using the field emission scanning electron microscopy (FESEM), the titanoecid spiders have a specialized sieve-like plate just in front of the anterior spinnerets. The other types of the silk spigots were identified as follows: ampullate, pyriform and aciniform glands. Two pairs of major ampullate glands send secretory ductules to the anterior spinnerets, and another 1~2 pairs of minor ampullate glands supply the median spinnerets. In addition, the pyriform glands send ductules to the anterior spinnerets, and the aciniform glands feed silk into the median and the posterior spinnerets, respectively. Characteristically, 2 distinct types (A & B types) of the aciniform spigots were identified in this spider, and the spigots of the aciniform B type are always detected at the posterior spinneret, however sexual dimorphism for spigot is unlikely to be exhibited in this species of spider.
... A gluey material from a combination of a flagelliform and two aggregate glands (Kovoor 1987;Moon & Kim 2005) is produced by most web-building spiders. The coelotine spider P. spinivulva lacks these triad spigots, as do other wandering spiders, such as the wolf spider Pardosa astrigera (Moon 1998), the funnel-web spider Agelena limbata (Park & Moon 2002), the green crab spider Oxytate striatipes (Moon & An 2006) and the lynx spider Oxyopes licenti (Moon 2006). ...
... A gluey material from a combination of a flagelliform and two aggregate glands (Kovoor 1987;Moon & Kim 2005) is produced by most web-building spiders. The coelotine spider P. spinivulva lacks these triad spigots, as do other wandering spiders, such as the wolf spider Pardosa astrigera (Moon 1998), the funnel-web spider Agelena limbata (Park & Moon 2002), the green crab spider Oxytate striatipes (Moon & An 2006) and the lynx spider Oxyopes licenti (Moon 2006). ...
The microstructural characteristics of the silk-spinning apparatus and its ecological significance in the coelotine spider Paracoelotes spinivulva were examined by field emission scanning electron microscopy, with the goal of understanding the properties and the evolutionary origins of these silk constructs. The silk apparatuses of this spider were composed of four basic types of silk-spinning spigot (ampullate, pyriform, aciniform and tubuliform), which connected with typical silk glands in the abdominal cavity. Of the three pairs of spinnerets, the posterior pairs were highly elongated along the body axis. Anterior spinnerets comprised two pairs of ampullate glands and approximately 70–80 pairs of pyriform glands in both sexes. Middle spinnerets had one to two pairs of ampullate spigots, three pairs of tubuliform spigots in females, and 50–60 (female) or 80–90 (male) pairs of aciniform spigots. An additional two pairs of tubuliform spigots in females and 70–80 (female) or 100–120 (male) pairs of aciniform spigots were counted on the spinning surfaces of the posterior spinnerets in both sexes. Although the coelotine spiders use their silk to catch prey, P. spinivulva characteristically do not have a typical “triad” spigot, including a flagelliform and two aggregate spigots, for capture thread production.
... Also associated with the anterior lateral spinnerets are many smaller spigots, each associated with a small pyriform gland. These are responsible for the creation of the attachment disk ( Figure 28D, E) that secures the dragline to the substratum (Kovoor 1987, Moon 2006). Figure 28. ...
... The arrangement and number of spigots vary between the species, sex, and age of the spider. [3][4][5][6] It is likely that the use of silk evolved once in spiders, and then over time has evolved into multiple different forms to fulfill different applications or functions for the spider. ...
Spider silk is of great interest because of its extraordinary physical properties, such as strength and toughness. Here we discuss how these physical properties relate to the way in which spiders have utilized this material in prey capture, forcing its evolution to a high-performance fiber. Female spiders can produce up to seven different types of silk, and all these have different physical properties, which relate to their various functions. The variation in properties are due to underlying differences in the proteins making up these silks. As our understanding of spider silk has increased in the recent years, it has been possible to produce recombinant versions of the respective proteins. Recombinant proteins open up the potential to produce synthetic silk fibers with properties similar to those of the natural spider silk threads.
The fine structural characteristics of the silk spinning apparatus in the titanoecid spiders Nurscia albofasciata have been examined by the field emission scanning electron microscopy (FESEM). This titanoecid spiders have a pair of medially divided cribella just in front of the anterior spinnerets, and the surface of the cribellum is covered by hundred of tiny spigots which produce numerous cribellate silk fibrils. The cribellar silks are produced from the spigots of the sieve‐like prate, and considered as a quite different sort of catching silk with dry‐adhesive properties. The other types of the silk spigots were identified as follows: ampullate, pyriform and aciniform glands. Two pairs of major ampullate glands send secretory ductules to the anterior spinnerets, and another 1–2 pairs of minor ampullate glands supply the middle spinnerets. In addition, the pyriform glands send ductules to the anterior spinnerets, and two kinds of the aciniform spigots feed silk into the middle (A type) and the posterior spinnerets (both of A & B types), respectively.
The effect of mechanical silking on the rate of protein synthesis in the major ampullate glands of the spider Araneus cavaticus has been investigated. Silking of one of the paired glands results in a greater rate of protein synthesis than in the unpulled control gland; in both in vivo and in vitro experiments. Our data indicate that the rate of protein synthesis can be regulated independently in the two silk glands. Radioisotopic label appears in the orb web more rapidly than one would expect were older silk drawn before newly synthesized silk.
TWO VENERABLE groups of spiders spin orb webs: the cnbellate Ulobon- dae, weavers of calamistrated sticky silk, and the ecribellate Araneidae, weavers of true viscid silk (Figs. 12.2, 12.1). "Cnbellate" spiders possess a cnbellum and a calamistrum. The cnbellum is a flat, complex spinning plate from which the cnbellate silk issues; the calamistrum is a comb of bristles on the fourth metatarsi used to comb the cnbellate silk from the cnbellum. "Ecnbellate" spiders lack these structures. Other aspects of the morphology of the two families of spiders also differ considerably, yet both groups spin very similar orb webs. When juxtaposed to the morphological disparity be- tween the spiders themselves, the similanty in the form of cheir webs and in the manner in which they are constructed has inspired a classic evolutionary controversythe single versus the dual origin of the orb web. Behavioral evidence has defined one group, "orb weavers," including some but not all cnbellate spiders, but morphological evidence has defined another, "Cn- bellatae," including some but not all orb weavers. The problem can be viewed as two contingent dilemmas. First, are all orb webs homologous as orb webs, and/or all cnbella homologous as cnbella? Second, if the answer to both of these questions is yes, then which homo- loguc is primitive and which derived, or do they both define the same group? There are several possible answers to these two dilemmas, and all have been suggested at one time or another in the history of the controversy. An addi- tional problem contributing to the controversy over the orb web is second- ary loss or complete modification of features in only some species of a monophyletic group. Occasionally, the species retaining the features are split off as a separate taxon defined by the retained primitive features. That taxon is not then synonymous with any real evolutionary lineage, and is
In the first half of this century, several workers observed small, seemingly glandular structures attached to the ampullate glands of spiders. Hence, they were termed accessory ampullate glands. In juvenile Araneus cavaticus, two pairs of these structures are present (starting at least with third instars), one pair attached to the major ampullate (MaA) glands and the other pair attached to the minor ampullate (MiA) glands. In adults, two pairs of accessory MaA glands and two pairs of accessory MiA glands are present. The two latter-formed pairs of accessory ampullate glands are clearly the remnants of those ampullate glands which atrophy shortly after adulthood is reached. Morphological similarities between these accessory ampullate glands and those present in juveniles provide an indication that the latter also have their origin in functional ampullate glands.
A reduction in the number of ampullate glands following the last molt occurs in many spiders. The reason(s) for these reductions is unknown. In penultimate spiders close to ecdysis, we have observed that while the larger pairs of MaA and MiA glands (those that are retained in the adult) are undergoing molt-related changes which apparently render them nonfunctional, their smaller counterparts are seemingly unaffected and functional. This raises the possibility that the principal role of the smaller ampullate glands may be to assume functions during the pre-ecdysial period which are normally in the domain of the larger ampullate glands. If true, then their degeneration after the last molt would make economic sense.
The presence of cylindrical spigots in juvenile females starting with fourth instars is documented.
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).
Proctolin-like immunoreactivity was detected in the prosoma of four species of araneid spiders. Proctolin levels as determined by radioimmunoassay ranged from 3.2 ± 0.6 ng proctolin per prosoma in Argiope aurantia to 8.7 ± 0.9 ng proctolin per prosoma in Araneus cavaticus. Immunohistochemical staining of prosomal sections revealed proctolin-positive tracts, fibres and varicosities in both the supraoesophageal and suboesophageal ganglia of Argiope aurantia and Araneus cavaticus. Using whole-mount preparations of spider hearts, proctolin immunoreactive fibres and varicosities were also observed in association with the myocardium. Proctolin-like bioactivity in partially purified prosomal extracts of Argiope aurantia and Araneus cavaticus co-eluted with synthetic proctolin using high-performance liquid chromatography. Application of 10−7 M synthetic proctolin to the neurogenic spider heart typically caused increases in the strength and rate of heart contractions, and occasionally produced a sustained contracture of the myocardium. Responses were similar in all four species examined. These data suggest that an endogenous proctolin-like peptide in these arachnids may act as a cardioregulatory neuromodulator or as a neurotransmitter in the central nervous system.
The spinning apparatus ofLinyphia triangularis, adult females and males, was studied with the scanning electron microscope and the main anatomical and histochemical characteristics of the silk glands, including the epigastric apparatus of males, are presented. The epigastric glands seem to be important for the construction of sperm webs. A detailed account of the use of the different kinds of silk in web building is given.
The spinning apparatus ofLinyphia closely corresponds to the araneid pattern. Characteristic of linyphiid spiders is the poor development of the aciniform glands. Corresponding to the minor importance of capture threads forLinyphia, the triads (aggregate and flagelliform glands) are less developed than in Araneidae.Linyphia make much less use of the secretions of the piriform glands for connecting threads than Araneidae. Capture threads adhere to other threads by their own glue; other threads seem mostly to be bound to one another by the secretion of the minor ampullate glands whose chemical properties, inLinyphia, appear especially adapted to this function. Neither the anatomical and histochemical data concerning the spinning apparatus nor the structure of the webs provide any indication of close relationships between Linyphiidae and Agelenidae, as was recently claimed.
- Denny M