Number Of Claws Research Articles

Phylogenetic analysis of Trechitae (Coleoptera: Carabidae) based on larval morphology, with a description of first‐instar Phrypeus and a key to genera

Abstract. Sixty‐nine characters of larval structure of twenty‐eight genera of the supertribe Trechitae (Coleoptera: Carabidae) were analysed phylogenetically. The monophyly of Trechitae is strongly supported with five unique synapomorphies. The monophyly of Zolini + Bembidiini + Pogonini is supported with two synapomorphies. We propose that the tribe Trechini is a sister group to them and its monophyly is supported with two unique synapomorphies. The inferred branching pattern of Trechini genera is (Perileptus + Thalassophilus) + (Amblystogenium + (Trechimorphus + (Trechus + Epaphius + Aepopsis + Trechisibus))); Perileptus is a member of Trechodina rather than Trechina. The monophyly of Zolini is not supported. The monophyly of Pogonini is supported with two unique synapomorphies; its sister group relationships remain obscure; the branching pattern of pogonine genera is (((Pogonus + Pogonistes) + Cardiaderus) + Thalassotrechus). No evidence for monophyly of the tribe Bembidiini (s. lato; including subtribes Bembidiina, Tachyina, Xystosomina, and Anillina) was found. The relationships of Phrypeus are obscure; no evidence could be found linking it with Bembidiina. Without Phrypeus, Bembidiina might be a monophylum with a single synapomorphy. Sinechostictus branches basal of (Bembidion + Asaphidion) and therefore should be treated as a separate genus. Tachyina and Xystosomina form a monophylum based on two unique synapomorphies; a close relationship with a monophyletic Anillina is suggested. Reduction of the number of claws from two to one in Trechitae has taken place twice: within Trechina (Trechus, Epaphius, Aepopsis and Trechisibus) and in (Zolini + Bembidiini + Pogonini). The previously unknown larvae of the isolated genus Phrypeus are described and illustrated. A key to all twenty‐eight analysed Trechitae genera based on characters of larvae and a list of larval autapomorphies for each genus are provided.

Some factors affecting Norway lobster (Nephrops norvegicus) cuticle polyphenol oxidase activity and blackspot development

SummaryPolyphenol oxidase (PPO) activity was measured in the cuticles of Norway lobsters caught over a period of 7 months. Increased PPO activity was observed between early August and early October 1995, coinciding with one of the reported annual periods of peak moulting activity, although a high PPO activity detected in May may have marked the spring moulting period. A relationship was found between the number of claws remaining on the Norway lobsters and the PPO activity, suggesting that exposing Norway lobsters to damage and stress is associated with an increase in PPO activity. No correlation was observed between initial PPO activity and blackspot development during storage of the Norway lobsters. This indicates that biochemical events occurring during storage are more important to blackspot development than the initial PPO level.

A new species ofDemodex(Acari: Demodecidae) from the black bear of North America,Ursus americanuspallas, 1780 (Ursidae)

Abstract Demodex ursi sp. nov. is described, in all life stages, from the black bear of North America, Ursus americanus. This demodecid inhabits the hair follicles of all body regions. Severe infestations are associated with extensive alopecia. Demodex ursi is most similar to D. ailuropodae from the giant panda, Ailuropoda melanoleuca, but the larvae differ in the number of claws per leg and there is no reported protonymphal stage in D. ailuropodae.

Supplementary biotin for sows: effect on claw integrity.

Eighty female pigs were fed, from 25 kg liveweight, either basal diets calculated to provide 32 micrograms available biotin/kg (control diet) or basal diets supplemented with 350 micrograms biotin/kg. Their claws were examined and lesions recorded at 170 days of age and when each of their first four litters was weaned. The incidence of horn 'defects' (superficial bruises, abrasions and cuts in the soft heel) remained at a low level throughout the trial. Neither the number of claws affected with lesions nor the number of lesions per sow differed between treatments at 170 days of age. Between 170 days of age and first weaning the incidence of hoof lesions increased greatly. At first weaning and for the remainder of the trial biotin supplemented sows had significantly fewer claw lesions per sow than controls (P less than 0.05 or greater). The predominant injuries to the foot were cracks which occurred mainly in two associated regions, the heel/toe junction and the heel, and the sidewall and adjacent white-line region of the toe. The differences in foot damage did not result in differences in culling rate. It was concluded that supplemention of the diet of breeding sows with biotin from an early stage of development made a significant contribution to the maintenance of their horn integrity.

The Natural Classification of the Rhombognathinae (Acari, Halacaridae)

THE Rhombognathinae are a group of herbivorous Acari inhabiting intertidal and shallow subtidal marine and estuarine waters. The group is cosmopolitan in distribution, although some of the genera are not, Rhombognathides Viets 1927 and Metarhombognathus Newell 1947 being known at present from only the temperate North Atlantic Ocean and adjacent subarctic or arctic waters.1 The genus Rhombognathus Trouessart 1888 is certainly cosmopolitan, and the genus Isobactrus Newell 1947 is probably so, being known from the North Atlantic, Adriatic Sea, the Kerguelen Archipelago, and the North Pacific Ocean. The latter record for the genus Isobactrus is based on undescribed species from the western United States and the Aleutian Islands. The subfamily was erected by Viets (1927, pp. 87-89) to include the single genus Rhombognathus, which was divided into three subgenera: Rhombognathus s. str. Trouessart 1888, Rhombognathides Viets 1927, and Rhombognathopsis Viets 1927. The subdivision was based solely on the number of claws on the tarsi. In the course of studies on the Halacaridae of eastern North America, the present author (1947, pp. 25-33) developed a new system of classification which produced a more natural grouping than Viets' system, and the four natural groups were considered to constitute four distinct genera. At that