В общем, забавно.
Все думаю помним неск. лет назад громкую публикацию Горба и сороварищи, которые открыли, что птицееды (в их случае Aphonopelma seemanni) тарзальными органами продуцирует паутину, что помогает лазать им по стеклу.
Так вот, в октябре вышла новая публикация Фернандо Перез-Милеса и коллег, опровергающая эти данные. Они считают их ошибкой, которая была допущена авторами в своё время.
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Silk production from tarantula feet questioned NATURE Journal| Vol 461 |22 October 2009
Arising from: S. N. Gorb et al. Nature 443, 407 (2006)
As with all spiders, tarantulas spin silk from specialized structures in
the abdomen called spinnerets, which are key features unique to the
group. Recently Gorb et al. reported that the zebra tarantula
Aphonopelma seemanni also secretes silk from its feet, which might
improve its ability to climb on vertical surfaces. Here we show that
when the spinnerets are experimentally sealed, the zebra tarantula
cannot secrete silk or similar threads, disagreeing with previous
reports by Gorb et al. Additional evidence also disagrees with leg
secretion of silk.
We placed four specimens of A. seemanni each in separate glass
containers with the floor and two vertical walls covered with 20 microscope
slides. Tarantulas remained in the container for 14 h, afterwhich
the slides were carefully examined. Seventy-two hours later, we sealed
the spinnerets of the same individuals with paraffin and repeated the
experiments. In the first trials with free spinnerets most slides (24 out
of 40 horizontal slides and 16 out of 40 vertical slides) showed silk
threads together with dislodged abdominal urticating hairs. None of
the slides in the trials with sealed spinnerets showed silk threads; we
found only urticating hairs. In both series of trials we observed the
spiders walking on vertical surfaces. In addition, we made transverse
cuts of A. seemanni tarsi and no structures interpretable as silk glands
or silk conduits were observed.
Tarantulas entangle silk threads from the spinnerets with their tarsi.
They often use hind legs to entangle silk, but we also observed
A. seemanni entangling with their other legs. This behaviour might
explain the presence of the thread footprints photographed by Gorb
et al. Tarantula silk released from spinnerets consists of multiple,
roughly parallel silk threads which are better observed when magnified.
This pattern could be maintained once the silk line is adhered
to the substrate, when combed or stepped by tarsal scopulae. Tarsal
structures interpreted as spigots by Gorb et al. are very different from
the diverse kinds of spigot reported for spiders. We found that the
structures reported by Gorb et al. are very similar in morphology and
size to fragments of tarsal thermosensory setae reported for other
tarantulas. In insects, a common origin or convergence was proposed
for silk spigots and sensory setae. The presence of conspicuous,
dense scopulae with spatulated setae on the ventral surface of tarsi
andmetatarsi of all tarantulas seemsincompatible with the presence of
spinning spigots in a lower layer, because scopula setae might interfere
with silk release. Furthermore, it has been explained that in
A. seemanni the friction with scopula setae is enough to guarantee
spider climbing.
During our observations, individuals of A. seemanni brushed
spinnerets with their hind-leg tarsi while walking and releasing silk
threads. The presence of abdominal urticating hairs with silk is indicative
of this brushing. We did not find evidence of silk-like secretion
through leg structures in tarantulas.
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А вот ответ "Чемберлена", т.е. Горба с сотоварищами на эту публикацию в этом же журнале:
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Gorb et al. reply
Replying to: F. Pe´rez-Miles, A. Panzera, D. Ortiz-Villatoro & C. Perdomo Nature 461, doi:10.1038/nature08404 (2009)
The data presented by Perez-Miles et al. call into question the
production of tarantula tarsal silk, but there remains substantive
evidence that would seem to contradict their assertion that tarsal silk
is solely due to abdominal silk entangled on to hind legs.
Tarsal silk traces appear consistently from all four pairs of legs, not
just the hind pairs that might regularly contact the spinnerets. As can
be seen in Fig. 2a of Gorb et al., tarsal silk is laid down in parallel
tracks, which seems incompatible with it being a secondary deposition
of silk combed on to the tarsi. Furthermore, scanning electron
microscopy examination of tarsal silk reveals a distinct broad area at
the beginning of the fibre that we interpret as an initial fluid. Presumably any fluid phase adhesive in abdominal silk would be lost in the transference to the tarsi. Another issue raised by Perez-Miles et al. is that adhesion of the spider to a clean dry surface could be accomplished entirely with the tarsal setae. The tarsal claws would certainly also suspend the animal from very rough surfaces. The
possibility of tarsal silk as a third adhesive mechanism implies that
that the biology of tarantulas is such that there is an advantage to
redundant systems.
Perez-Miles et al. also propose that the ‘spinneret’ structures we
found are sensory structures, which is intriguing because similarity
between the two structures may indicate a common developmental
origin. Indeed, it has been suggested that the convergently evolved
tarsal silks in web-spinner insects and dance flies arise from derived
sensory cells. We remain satisfied that the most plausible explanation
for our observations is the existence of tarsal-silk-producing
structures scattered within the setae on tarantula tarsi.
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Поедать оотеки едва ли могут... После "смены" - всегда так бывает, т.к. обычно это делается неправильно. При смене или чистке объёма с тараканами никогда нельзя полностью заменять субстрат - это останавливает развитие колонии. Так что надо подождать. Да, и ещё. 25-30С - это неправильные параметры. 25 - вообще практически недопустимая температура для этого вида, 30 - средне-хорошая. Догрев до 35 очень желателен для хорошего прироста колонии. И давайте уже заканчивать называть туркестанского таракана Shelfordella tartara. Это уже несколько лет как во всём мире неправильное название. Правильное название вида - Blatta lateralis.
