Behavioural variation in limulids (Xiphosurida) from the Middle Jurassic of the Cleveland Basin, Yorkshire, UK, as deduced from their traces: a review and reappraisal

2020 ◽  
Vol 63 (3) ◽  
pp. pygs2020-005
Author(s):  
Mike Romano
Keyword(s):  
Middle Jurassic ◽  
Horseshoe Crab ◽  
Marine Strata ◽  
Behavioural Patterns ◽  
Horseshoe Crabs ◽  
Jurassic Rocks

The paper is a study of horseshoe crab (limulid) behaviour, based on their ichnites from the Middle Jurassic rocks of the Cleveland Basin, Yorkshire, UK, from a succession spanning a period of c. 8 myr. Five named ichnospecies have been recognized from this sequence as having a limulid maker: Selenichnites hundalensis, S. rossendalensis, Kouphichnium aff. variabilis, K. cf. arizonae and Crescentichnus tesiltus, as well as unassigned ichnospecies (K. isp. indet., S. isp., S. isp. indet., and C. ispp. indet.). These traces have been interpreted as showing behavioural patterns during burial, feeding, locomotion and probing. The occurrence of these traces in both non-marine and marine strata together with their presumed lifestyle is compared to what is known of extant horseshoe crabs, and any difference in lifestyle is discussed.

Bled

2018 ◽  
Author(s):  
Lisa Jean Moore
Keyword(s):  
United States ◽  
Health Care ◽  
Quality Control ◽  
Horseshoe Crab ◽  
The United States ◽  
Standard Test ◽  
Nonhuman Animal ◽  
Laboratory Studies ◽  
Health Care Demand ◽  
Horseshoe Crabs

In 1964, Limulus amoebocyte lysate (LAL), developed from horseshoe crab blood, was discovered as an effective pryogen test. Limulus blood reacts to endotoxins by forming a gel. The LAL test, constructed from horseshoe crab amoebocytes, has become the standard test in the United States, Europe, and Asia to test pharmaceutical injectables and pharmaceutical insertables for biomedical and veterinary uses. Without it, endotoxins could contaminate all of our laboratory studies, our bodies, and other nonhuman animal bodies. We’ve made horseshoe crabs indispensable to our human and veterinary biomedicine. We need their blood, and as health care demand grows, we will need more and more. I explain how blood donations are detrimental to the crabs. Furthermore, I explain how the LAL test is a not lifesaving test but is instead used for quality control. Even with all of this information and the viability of a synthetic alternative, the bureaucracy surrounding the procedure for switching to the synthetic alternative will prevent the switch from happening until most of the crabs have died. They are not valued like humans are; they are instead valued for their use to humans and will be valued that way until they are used up.

Horseshoe crabs as potential sentinel species for coastal health: juvenile haemolymph quality and relationship to habitat conditions

2018 ◽  
Vol 69 (6) ◽  
pp. 894 ◽  
Author(s):  
Billy K. Y. Kwan ◽  
Virginia K. Y. Un ◽  
S. G. Cheung ◽  
Paul K. S. Shin
Keyword(s):  
Horseshoe Crab ◽  
Anthropogenic Activities ◽  
Monitoring Program ◽  
Significant Negative Correlation ◽  
Sentinel Species ◽  
Crab Species ◽  
Horseshoe Crabs ◽  
The Difference ◽  
Lead Nickel ◽  
Further Development

As an interface between terrestrial and marine environments, coastal and estuarine areas are particularly prone to various pollution stresses. Identification of sentinel species is, therefore, essential to provide precautionary information on coastal health conditions. Given their significant ecological roles in estuarine ecosystems, horseshoe crabs are a potential species to indicate the general health status of coastal habitats. The present study demonstrated that the changes in haemolymph composition pattern of two Asian juvenile horseshoe crab species (Tachypleus tridentatus and Carcinoscorpius rotundicauda) are sensitive to reflect heavy metal (lead, nickel and iron) and nutrient (nitrate and ammonia) concentrations of intertidal sediments. In particular, a significant negative correlation was found for the amebocyte viability and ratio of granular–spherical to granular–flattened and degranulated dendritic-like morphological states of amebocytes in juvenile haemolymph with nitrate and lead concentrations respectively. There were also significantly higher concentrations of haemolymph haemocyanin and plasma protein in juvenile C. rotundicauda than in T. tridentatus on the same shore, possibly being related to the difference in foraging habitats of these two horseshoe crab species. Such non-lethal sampling of haemolymph from juvenile horseshoe crabs can be useful for a further development of the monitoring program in assessing potential environmental impacts by anthropogenic activities.

First post-Triassic temnospondyl amphibians from the Shan-Thai block: intercentra from the Jurassic of peninsular Thailand

1994 ◽  
Vol 131 (6) ◽  
pp. 837-839 ◽  
Author(s):  
Eric Buffetaut ◽  
Lertsin Raksaskulwong ◽  
Varavudh Suteethorn ◽  
Haiyan Tong
Keyword(s):  
Middle Jurassic ◽  
Precise Identification ◽  
Jurassic Rocks ◽  
Northeastern Thailand

AbstractTwo temnospondyl intercentra from non-marine middle Jurassic rocks at Mab Ching, in the southern peninsula of Thailand, are the first remains of post-Triassic labyrinthodont amphibians to be reported from the Shan-Thai block. They closely resemble an intercentrum recently reported from the middle Jurassic of the Khorat Plateau of northeastern Thailand, which is part of the Indochina block. Although the Mab Ching specimens are too fragmentary to warrant a precise identification, they confirm that temnospondyl amphibians were widespread on the various Asian continental blocks in the Jurassic.

Visual performance of horseshoe crabs day and night

1991 ◽  
Vol 7 (3) ◽  
pp. 179-189 ◽  
Author(s):  
Maureen K. Powers ◽  
Robert B. Barlow ◽  
Leonard Kass
Keyword(s):  
Horseshoe Crab ◽  
Average Distance ◽  
Natural Behavior ◽  
Object A ◽  
Circadian Changes ◽  
Horseshoe Crabs ◽  
Normal Environment ◽  
And Function ◽  
Daily Changes

AbstractA circadian clock modulates the structure and function of the lateral eyes of Limulus polyphemus, greatly increasing their sensitivity at night. During the mating season, male Limulus are visually attracted both day and night to females and objects that resemble females. This paper asks how well Limulus can see day and night, and whether the circadian changes in retinal sensitivity might influence the ability of these animals to find mates. We recorded the visual behavior of male and female horseshoe crabs in the vicinity of an object – a cement hemisphere (29.5 cm diameter) similar in size and shape to a female horseshoe crab – placed in a mating area near Mashnee Dike, Bourne, Massachusetts. Males oriented toward this target from an average distance of 0.94 m during the day and 0.88 m at night; and females appeared to avoid the target. We conclude that males can see potential mates at night almost as well as they can during the day. Apparently the circadian changes in the retina help compensate for the daily changes in illumination in the animal's normal environment. This study provides the first evidence for a role of visual circadian rhythms in an animal's natural behavior.

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