Troponin I is the actomyosin ATPase inhibitory subunit present in the thin filament regulatory complex. The complete amino acid sequence of crayfish tail muscle troponin I has been determined. The protein is composed of 201 amino acid residues and has a molecular weight of 23,547. The N terminus is blocked, likely by an acetyl group. Crayfish troponin I shows a rather low (20-25%) sequence iden...

Rapid transitions in ecosystem structure, or regime shifts, are a hallmark of alternative stable states (ASS). However, regime shifts can occur even when feedbacks are not strong enough to cause ASS. We investigated the potential for ASS to explain transitions between dominance of an invasive species, rusty crayfish (Orconectes rusticus), and native sunfishes (Lepomis spp.) in northern Wisconsi...

Crayfish depend on sensilla, small cuticular structures occurring all over their bodies to acquire information about their outside environment. Sensilla contain sensory neurons that are either mechanoreceptive or chemoreceptive. The tail fan of crayfish houses numerous sensilla that contain mechanoreceptor neurons and their activation by animals approaching from behind elicits a tail-flip escap...

The gross microscopical anatomy of the crayfish antennal gland has been well and repeatedly characterized (Marchal, 1892; Peters, 1925; Maluf, 1939). Examination of the anatomy of the organ has yielded little information elucidating its basic functional mechanism. Since the work of Schlieper & Herrmann (1930) it has been known that the crayfish excretes a urine that is markedly hypotonic to the...

The effect of acute and chronic cold exposure on heart rate (HR) and neuronal function in crayfish Procambarus clarkii and prawns Macrobrachium rosenbergii was addressed. This is particularly important since prawn farms of this species are used for aquaculture in varied climates world wide. The success of P. clarkii as an invasive species throughout the world may in part be due to their ability...

Three-quarters of the world’s crayfish fauna are found in the US and Canada. Small natural ranges, habitat disturbance, and introduced crayfish species threaten many species, and nearly 1⁄2 are imperiled. Naturally small ranges are considered the leading factor for crayfish vulnerability to loss, yet species with small ranges have received little research attention. Orconectes saxatilis is a ra...

Dams and impoundments, both large and small, affect downstream physicochemical characteristics and upand downstream biotic communities. I tested whether small dams and their impoundments altered downstream crayfish assemblages in northern Mississippi. I sampled crayfish and measured physicochemical variables at 4 sites downstream of impoundments (outlet sites) and 4 sites not influenced by impo...

The stone crayfish, Austropotamobius torrentium, is a European freshwater crayfish. Although this species relatively widespread throughout the continent, it undergoing significant declines its range. However, as decline rates have not been quantified in detail, classified data deficient by IUCN Red List of Threatened Species. present study describes development and validation two species-specif...

Abstract The white-clawed crayfish, Austropotamobius pallipes is endangered throughout its entire biogeographic range in Europe due to infection with Aphanomyces astaci (crayfish plague) and habitat deterioration. Ex situ propagation of increasing importance safeguard genetic resources enable restocking measures after the pathogen’s disappearance. This study aimed quantify impact crude protein ...