Fri, 10 Sep 2010 19:47:43 +0000 1800 This is the RSS feed of the last ten file submissions accepted into our database. This RSS feed is always up to date as it is dynamically updated.

The vision of Palaemonetes is of particular interest in view of extensive
studies of the responses of its chromatophore systems and eye pigments
to light. The spectral sensitivity is here examined under conditions of dark
adaptation and adaptation to bright colored lights. In each case the relative
number of photons per one-fiftieth see flash needed to evoke a constant peak
amplitude (usually 25 or 50/zv) in the electroretinogram (ERG) was measured
at various wavelengths throughout the spectrum. The sensitivity is the reciprocal
of this number. In dark-adapted animals the spectral sensitivity curve consists
of a broad, almost symmetrical band, maximal at about 540 m/z, with a shoulder
near 390 m#. Adaptation to bright red or blue light, left on continuously
throughout the measurements, depresses the 540 m# peak without notably
changing its shape or position, implying that only one visual pigment operates
in this region. Adaptation to red light, however, spares a violet-sensitive system,
so that a high, narrow peak at 390 m/z now dominates the spectral sensitivity
function. The 540 and 390 m/z peaks are apparently associated with different
visual pigments; and these seem to be segregated in different receptor systems,
since the associated ERG's have markedly different time constants. It is suggested
that these two sensitivity bands may represent the red- and violet-sensitive
components of an apparatus for color differentiation.]]> Fri, 03 Sep 2010 09:17:06 +0000 418 This is an extensive document on the DNA sequencing of Australian Cherax populations. Sun, 22 Aug 2010 06:23:45 +0000 417
Yabbies larger than 25 g tended to use their walking legs to push the Daphnia nearer to their third maxilliped which would then force or scoop the
zooplankton towards the mouthparts. A short-term feeding trial showed that there was no significant difference between size classes in regards to zooplankton consumption (P[0.05). Capture efficiency of live Daphnia by yabbies less than 15 g was significantly lower (76%, P = 0.008) than the three larger size classes (93.6%). Yabbies less than 15 g consumed a significantly (P\0.001) higher percentage (5.2%) of their body weight than the other size classes (1.1%, 0.8%, and 0.6%, respectively). In the presence of both live zooplankton and a pellet diet, yabbies spent significantly (P = 0.005) more time feeding on zooplankton (85%) than on inert pellets (15%). This was the first study to quantify zooplankton consumption by yabbies and the results provide insights into understanding the trophic role of freshwater crayfish in structuring zooplankton communities and the husbandry management of crayfish farming.]]> Thu, 29 Jul 2010 20:30:05 +0000 416 the native Pacifastacus gambelii is widespread and often abundant in the Bear and Weber river drainages and is
occasionally represented in smaller tributaries to the Great Salt Lake and to the Raft River. Pacifastacus leniusculus was
collected from Utah County and Procamharus clarkii from Tooele County; the origin of these populations is not known.
The nonnative crayfish Orconectes virilis is currently abundant in the Virgin, Price, and Duchesne river basins and the
Glen Canyon, Flaming Gorge, Deer Creek, and Starvation reservoirs; it is expanding in Huntington North, Scofield,
and Willard reservoirs. Further work is required to develop a more complete inventory and monitor the impacts on
acjuatic ecosystems of expanding nonnative crayfish populations. Surreptitious stockings can be dealt with only if the
public is made aware of the adverse consequences of ill-conceived introductions.]]> Thu, 22 Jul 2010 20:36:20 +0000 415 they are hardy. The life cycle
can be easily manipulated to fit a
variety of cultural situations, and
they can be easily integrated into
agricultural crop rotation. The most
common crawfish/agronomic crop
rotations are rice/crawfish/rice,
rice/crawfish/soybeans, and crawfish/
rice/set-aside. The various
agricultural/crawfish culture cycles
are as follows:]]> Tue, 29 Jun 2010 21:36:14 +0000 414
Common Name.—None. Morgan (1988) did not designate a common name in the original description, and we are unaware of any common name having been applied subsequently. We suggest ‘The Jagara Hairy Crayfish’ would be suitable.]]> Sun, 27 Jun 2010 08:24:57 +0000 413 An assessment of genus Euastacus (49 species)
versus IUCN Red List criteria

Jason Coughran and James M. Furse 2010


1. INTRODUCTION

Euastacus is the largest of the 10 Australian crayfish genera with 49 species described,
comprising 37% of all Australian freshwater crayfish species. Euastacus includes some of the
largest, and some of the rarest, species in the World, and the genus is often referred to broadly as
the “Spiny Crayfish” genus of Australia, due to some species featuring impressive arrays of
spines on the thorax, abdomen and chelae. In addition, many species are very colourful, and this
cludes various shades of blue, green, red, yellow, purple and orange.]]> Mon, 17 May 2010 05:58:53 +0000 412 In this study, the possibility of heavy metals accumulation with two groups of Iranian and Australian
earthworms in sewage sludge vermicompost was investigated. Eisenia fetida was the species of earthworms
used in the vermicomposting process. The bioaccumulation of Cr, Cd, Pb, Cu, and Zn as heavy metals by
Iranian and Australian earthworms was studied. The results indicated that heavy metals concentration
decreased with increasing vermicomposting time. Comparison of the two groups of earthworms showed that
the Iranian earthworms consumed higher quantities of micronutrients such as Cu and Zn comparing with the
Australian earthworms, while the bioaccumulation of non-essential elements such as Cr, Cd, and Pb by the
Australian group was higher. The significant decrease in heavy metal concentrations in the final
vermicompost indicated the capability of both Iranian and Australian E.fetida species in accumulating heavy
metals in their body tissues.]]> Mon, 12 Apr 2010 03:09:50 +0000 411 In 2005 a new, non-indigenous crayfish species was discovered in the Dessoubre River (eastern France). The species was initially considered as Orconectes rusticus (Girard, 1852). However, an examination of form I males caught in 2007 revealed that the species is in fact Orconectes juvenilis (Hagen, 1870), a closely related congener of O. rusticus. According to our knowledge, this is the first record of O. juvenilis outside the North American continent. The ecological implications as well as the possible impact on the native European crayfish are discussed briefly. Wed, 09 Sep 2009 23:52:25 +0000 410 around the world because of its large size potential and resemblance to high-priced American lobsters. However,
little is currently known of the nutrient requirements and practical diet formulations for red claw. Lecithin has been shown to be required in the diets of several crustacean species, but there are no reports of dietary lecithin requirements for red claw.]]> Tue, 08 Sep 2009 12:29:58 +0000 409