Activity levels of Nautilus in the wild

Article Abstract:

A study of the activity levels in the wild of the Nautilus is reported. The aim was to understand why nautiloids survived relatively unchanged from the Ordovician, while ammonites and all other ectocochleate cephalopods became extinct. The study involved obtaining high-resolution tracks of animal position and depth and telemetered jet pressures to examine animal lifestyle and economics. The results showed that Nautilus is more active in the wild than in captivity, but expend less energy. The animal reduces transport energy costs by taking advantage of vertical movement. Also, it moves to deeper, cooler waters after feeding to allow a single feeding to last longer.

Energy metabolism, Bioenergetics, Animal locomotion

---

Nautilus and the art of metabolic maintenance

Article Abstract:

The cephalopod mollusk Nautilus can survive for at least a day in severe hypoxic environments by suppressing its aerobic metabolic rate to 4 to 8% of that at normal oxygen levels. The reduction in metabolic rate decreases the activity level with interspersed periods of high activity followed by longer inactive periods. The ventilatory processes stop, cardiac output decreases and the heart beat slows down. The blood that has a high oxygen affinity is oxygenated at the venous end across the superficially loaded vena cava.

Analysis, Hypoxia, Anoxia, Metabolic regulation

---

Why squid can breathe easy

Article Abstract:

Squids in the cold deep oceans have huge gill areas and low blood-water barrier thicknesses which allow them to survive in low oxygen areas. The gills are very fragile and are not a part of the buccal apparatus. This removes the danger to the gills from sharp bones and pieces of cuticle. The squids have a high oxygen diffusion ability and can move quickly even in areas of low oxygen. The high oxygen diffusion rate is probably the reason for the large number of cephalopods present in the deep seas.

Measurement, Respiration, Marine invertebrates, Squids, Squid

Similar abstracts:

• Abstracts: Essential role for ZAP-70 in both positive and negative selection of thymocytes. A mouse knock-in model exposes sequential proteolytic pathways that regulate p27Kip1 in G1 and S phase
• Abstracts: Evolution in vitro of an RNA enzyme with altered metal dependence. Leslie Orgel
• Abstracts: Lifestyles of the rich and famous? Sharks: myth and mystery. Iceland, naturally
• Abstracts: Individual mating success, lek stability, and the neglected limitations of statistical power. Environmental conditions and male morphology determine alternative mating behavior in Trinidadian guppies
• Abstracts: The role of transferrin-receptor variation in the host range of Trypanosoma brucei. A structural motif in the variant surface glycoproteins of Trypanosoma brucei

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.