Respiratory responses of aquatic insects to low oxygen concentration.

Aquatic Insects: Hemimetabolous Insects – Plecoptera

Aquatic nitrogen transformations at low oxygen concentrations.

Nitrite and nitrous oxide made up 40% of the hypolimnetic dissolved inorganic nitrogen in mesotrophic Lake Rotoiti, New Zealand, prior to hypolimnetic anoxia. Up to 120 mg of N m-3 as nitrite and 20 mg of N m-3 as nitrous oxide accumulated, whereas dissolved-oxygen concentrations remained between 1.0 and 0.2 g m-3 and were totally consumed when the hypolimnion became completely anoxic. Assays o...

Respiratory control in aquatic insects dictates their vulnerability to global warming

Forecasting species responses to climatic warming requires knowledge of how temperature impacts may be exacerbated by other environmental stressors, hypoxia being a principal example in aquatic systems. Both stressors could interact directly as temperature affects both oxygen bioavailability and ectotherm oxygen demand. Insufficient oxygen has been shown to limit thermal tolerance in several aq...

The respiratory responses of Carcinus maenas to declining oxygen tension.

The degree of respiratory independence shown by Carcinus under conditions of declining oxygen tension is dependent on the animal's level of activity. Inactive Carcinus are capable of maintaining respiratory independence down to a Po2 of 60-80 mmHg. This is achieved primarily by an increase in ventilation volume such that the amount of oxygen made available at the respiratory surfaces remains co...

Myocardial and systemic vascular responses to low concentration of carboxyhemoglobin.

Carboxyhemoglobin alters the oxyhemoglobin dissociation curve in such a manner that oxygen is released to the tissues with great difficulty and at a lower oxygen tension. The known effects on heart and brain of breathing low concentrations of carbon monoxide are primarily related to this leftward shift and perhaps also to its combination with myoglobin and certain iron-contain­ ing enzymes. Hem...