Chirocephalus

Abstract: HAEMOGLOBIN in solution in the blood plasma is found in numerous entomostracan Crustacea. Ray Lankester first discovered it in Chirocephalus, observing the absorption bands of oxyhaemoglobin with a microspectroscope1, and soon afterwards found it in Daphnia. The wave-length of the α-band differs among species within the genus Daphnia 2. The pigment also occurs in the blood of other Cladocera, for example: Sida, Simocephalus, Moina, Bosmina, Ilyocryptus, Eurycercus, Leydigia, Chydorus, etc., but not in Leptodora. The haemoglobin of Ceriodaphnia has a higher oxygen affinity than that of Daphnia, and the former lives in fouler water3. Haemoglobin is present, too, in Phyllopoda : it is in the blood of Conchostraca (Lynceus, Leptestheria 4, Limnadia), Anostraca (Chirocephalus, Artemia 5,6) and Notostraca (Triops 7, Lepidurus). It may be universal in the blood of the Phyllopoda. Among the Ostracoda, haemoglobin occurs in Cypria 8 and Pseudocypris.

Abstract: Summary 1 The commonly accepted view that Chirocephalus feeds chiefly or entirely on minute suspended particles is incorrect Its chief food consists of detritus 2 There is also a filter-feeding apparatus which is here described for the first time 3 The larger food particles consisting of filamentous algae and the leaves of mosses etc, are not sucked into the median groove, but are pushed in by the endites and pushed towards the mouth by the spines and setae on the basal endites The basal endites are thus gnathobasic lobes, which may act in apposition 4 Water which may be carrying minute suspended particles finds its way into the inter-limb space probably by the 7th endites and exopodites, together forming a series of vortices which converge Suspended particles which are drawn into the median groove cannot settle there by reason of the increase in the rate of flow, nor is it likely that they could be caught by an existing secretion of mucus 5 As the limbs move backwards the water at their base is under pressure and enters the median groove after passing through the filter process 6 The movement of the limbs is irregular and only roughly metachronial Any account of feeding, swimming, or respiratory process which demands precise co-ordination of the limbs is untenable 7 The limbs are highly muscular, and both the endites and exites are definitely controlled both during the forward and backward movements 8 The real action of the limbs is highly complicated, and its complete investigation would involve more mathematical data than are available at the present moment 9 It is suggested that the chief swimming-limb is the exopodite which, functions as a propeller and not as a paddle or oar 10 The view taken by Sars that the proepipodites function as covering scales is upheld They definitely do not function as valves 11 The view taken by Sars that the primary function of the phyllopod post oral limb is respiratory is upheld 12 The present habitat of Chirocephalus diaphanus must be entirely different from any which existed in early palaeozoic times Speculations dealing with the phylogeny of Crustacea, based as they must be almost entirely on structure, require considerable caution

Abstract: This study analysed the levels of genetic differentiation within and among the six Italian species of the fairy shrimp genus Chirocephalus by analysing electrophoretic polymorphisms at 22 enzymatic loci and by sequencing a 665-bp fragment of the mitochondrial gene encoding for subunit I of cytochrome oxidase. The allozyme data revealed different levels of intra-specific differentiation; mean θ estimates were low in Chirocephalus salinus, higher and comparable in C. diaphanus and C. kerkyrensis, while C. ruffoi was the most genetically structured species. At the inter-specific level, C. marchesonii was the most differentiated species, both for allozymes and mtDNA. Phylogenetic relationships deduced from allozymes and mtDNA were not always consistent with each other. This highlights the differences in performance of the two classes of molecular markers and the need of different independent strategies of data analysis to search for possible incongruence. Neither allozymes nor mtDNA supported monophyly of the diaphanus-group, previously recognized on the basis of the morphology of appendages (antennae and penes). In contrast the molecular results were consistent with the great heterogeneity in resting egg morphology among representatives of the diaphanus-group.

Abstract: We report the finding of three anostracan species, Chirocephalus skorikowi Daday, 1913, Branchinecta orientalis Sars, 1901 and Branchinella spinosa. Milne-Edwards, 1840 in different localities in northwestern Iran. C. skorikowi was recorded in a lake at an elevation of 2400 m, whereas B. orientalis was found in a pond at 1280 m a.s.l. Co-existing B. spinosa and B. orientalis were collected in a pool close to the town of Tabriz, formerly indicated by Brehm (1954) as Estakr Chah, presently named EalGoli. Unlike Brehm (1954), we did not find Streptocephalus in the area of Tabriz.