Presence of abdominal appendages in females of Caprella equilibra Say, 1818 (Peracarida, Amphipoda): is Metacaprella Mayer, 1903 a valid genus?

Crustaceana ◽  
2012 ◽  
Vol 85 (1) ◽  
pp. 71-79 ◽  
Zootaxa ◽  
2012 ◽  
Vol 3238 (1) ◽  
pp. 39 ◽  
Author(s):  
FELIPE LORENZ SIMÕES ◽  
AUGUSTO FERRARI ◽  
JOCÉLIA GRAZIA

The genus Elsiella Froeschner, 1981 is validated based on the analysis of a recently found male specimen of E. plana(Walker, 1867). A cladistic analysis comprising a data set of 40 morphological characters and 22 taxa, including the generaElsiella, Serdia Stål, Similliserdia Fortes & Grazia, Neotibilis Grazia & Barcellos, and Tibilis Stål, was performed. Elsiellaplana is redescribed and illustrated. Maps are provided for Elsiella and Serdia with biogeographical considerations for Serdia.


1878 ◽  
Vol 169 ◽  
pp. 505-521 ◽  

The following paper contains an account of observations on the development of the species Cymothoa œstroides and C . parallela of Milne Edwards; but the forms of the young seem to show that several species are really included under these two names. In the early stages of development the only observable difference that exists between the embryos is one of size, but in the later stages they differ very markedly from each other in their external characters. From adult individuals answering the description of C . œstroides I have obtained four varieties of embryos: two with long antennae and two with short.* In the two former the first pair of antennae are but slightly longer than the head, while the second pair are longer than the body; the eyes are small. In one of the varieties thus characterised the abdominal appendages are fringed with long hairs (fig. 20), and in the other they are smooth.


1981 ◽  
Vol 90 (1) ◽  
pp. 85-100
Author(s):  
CHARLES H. PAGE

Postural extensions of the abdomen of the crayfish, Procambarus clarkii, could be evoked by mechanical stimulation of a single thoracic leg. Movement of a single leg joint was sufficient to initiate an extension response. Vigorous abdominal extensions were initiated either by depression of the whole leg (WLD) or by flexion of the mero-carpal joint (MCF). Weaker extension responses were obtained by depression of the thoracic-coxal and coxo-basal joints. Similar stimulation of the chelipeds did not elicit an abdominal extension response. Single-frame analysis of motion pictures of crayfish responding to WLD or MCF stimulation of a 2nd thoracic leg showed that the responses evoked by the two different stimulus situations were nearly identical. They differed principally in the responses of the leg located contralateral to the stimulated leg. Movements of most of the cephalic, thoracic and abdominal appendages accompanied the abdominal extension response. Only the eyes remained stationary throughout the response. The mean values of the latencies for the initiation of appendage movement ranged from 125 to 204 ma; abdominal movement had a mean latency of about 220 ms. The abdominal extension reflex resulted from the activity of the tonic superficial extensor muscles. The deep phasic extensor muscles were silent during the response. The mean latencies for the initiation of superficial extensor muscle activity by WLD and MCF stimulation were 53·7 and 50·0 ms respectively.


Parasitology ◽  
1960 ◽  
Vol 50 (1-2) ◽  
pp. 7-11 ◽  
Author(s):  
G. P. Jain
Keyword(s):  

While working on the life cycle of Cercaria mehrai Faruqui, 1930, the author obtained the adults from the intestine of experimentally infected white rats. The trematodes thus obtained were reported as belonging to the genus Paryphostomum Dietz, 1909. In view of the facts that the collar spines are 43 in number, the vitellaria are confluent in the post-testicular region and the cirrus-sac extends far behind the acetabulum, P. mehrai is transferred to the genus Artyfechinostomum Lane, 1915, which is, in author's opinion, a valid genus (Jain, 1959).


1938 ◽  
Vol s2-81 (321) ◽  
pp. 127-150
Author(s):  
A. E. NEEDHAM

1. In the female Asellus aquaticus it is the first pair of pleopods which is missing and not the second pair, as was usually held. This condition is the result of an inhibition on the development of the last thoracic and first abdominal segments in later brood-pouch stages, an inhibition which is only temporary in the last thoracic segment and in the first abdominal segment of the male. 2. The resemblance between the second abdominal appendages in the female and the first pair of the male is therefore purely convergent. 3. The strong probability that the same condition holds throughout the sub-order Asellota is supported bj a comparison of adult morphology, and should be verified by embryological study. It is more usual in Crustacea for appendages to be lost at the end than in the middle of a series. 4. The structure of the copulatory apparatus of the adult male Asellus is extremely complex, and apparently closely adapted to its mode of function. In contrast the female apparatus is of the simplest. 5. Points of evolutionary and genetical interest are raised by the condition of these appendages in the two sexes.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3311 ◽  
Author(s):  
Lüzhou Li ◽  
Qiang Li ◽  
Xiaoyu Lu ◽  
Xijun Ni

The Early to Late Oligocene Propalaeocastor is the earliest known beaver genus from Eurasia. Although many species of this genus have been described, these species are defined based on very fragmentary specimens. Propalaeocastor irtyshensis from the Early Oligocene Irtysh River Formation in northwestern Xinjiang, China is one of the earliest-known members of Propalaeocastor. This species is defined on a single maxillary fragment. We revise the diagnosis of P. irtyshensis and the genus Propalaeocastor, based on newly discovered specimens from the Irtysh River Formation. The dental morphology of P. irtyshensis is very similar to other early castorids. The caudal palatine foramen of P. irtyshensis is situated in the maxillary-palatine suture. This is a feature generally accept as diagnostic character for the castorids. On the other hand, P. irtyshensis has two upper premolars, a rudimentarily developed sciuromorph-like zygomatic plate, and a relatively large protrogomorph-like infraorbital foramen. Some previous researchers suggested that Propalaeocastor is a junior synonym of Steneofiber, while other took it as a valid genus. Our morphological comparison and phylogenetic analysis suggest that Propalaeocastor differs from Steneofiber and is a valid genus. We also suggest that Agnotocastor aubekerovi, A. coloradensis, A. galushai, A. readingi, Oligotheriomys primus, and “Steneofiber aff. dehmi” should be referred to Propalaeocastor. Propalaeocastor is the earliest and most basal beaver. The origin place of Propalaeocastor and castorids is uncertain. The Early Oligocene radiation of castorids probably is propelled by the global climate change during the Eocene-Oligocene transition.


2008 ◽  
Vol 82 (6) ◽  
pp. 1220-1220 ◽  
Author(s):  
Alycia L. Stigall

The genus Bicarinella Rode et al., 2003 was erected for a new hipponicharionid bradoriid species described from the early Cambrian of East Antarctica, characterized by a subtriangular carapace with prominent anterior and posterior lobes developed as two distinctive, sharp ridges (bi = two, carina = ridges). Unfortunately, the name Bicarinella is preoccupied by two different gastropod genera: Bicarinella Waterhouse 1966, a Permian gastropod from New Zealand and Australia, and Bicarinella Akopyan 1976, a gastropod from Late Cretaceous strata of Armenia, Serbia, Romania, Tajikistan, and Egypt (Mennessier, 1994; Banjac, 1998; Pana, 1998). Mennessier (1994) transferred Bicarinella Akopyan, 1976 from its original status as an independent taxon to a subgenus of Pseudomesalia Douvillé 1916, but subsequent workers have continued to consider Bicarinella a valid genus (Pena, 1998; Banjac, 1998). Due to the preoccupation, the bradoriid genus is herein renamed in accordance with the requirement of the International Code of Zoological Nomenclature (1999, article 60). It is also noted here that the one of the two distinct gastropod genera should be renamed. The name Bicarinellata (bi = two, carina = ridges) is proposed as a replacement name for Bicarinella Rode et al., 2003. This name retains the original prefixes to preserve taxonomic stability as much as possible. The type species of Bicarinellata is B. evansi by original designation (Rode et al., 2003).


Zootaxa ◽  
2018 ◽  
Vol 4450 (5) ◽  
pp. 501 ◽  
Author(s):  
LOUWRENS P. SNYMAN ◽  
CATHERINE L. SOLE ◽  
MICHAEL OHL
Keyword(s):  

The Mantispinae (Neuroptera: Mantispidae) genera of the Oriental and Palearctic regions are revised. A morphological key to the genera is generated. Austroclimaciella, Campancella, Mantispa, Mantispilla, Necyla, Stenomantispa and Tuberonotha are redescribed. The Ohl (2004) catalogue is updated for the relevant genera. Sagittalata (= Perlamantispa) is assigned as a synonym of Mantispilla which is restored as a valid genus. Orientispa is assigned as a synonym of Necyla. 


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