Trying to determine the age of an animal can be difficult. There are certain features that can assist in this determination, however, many researchers will rely on straight length to place animals in a life history category (an age class).  At the bottom of this page you can find standard lengths for various age classes for California sea lions from the published literature. However, with experience you will be able to pick out many of the other features that will alert you to whether an animal is a neonate, an adult, or somewhere in between.

Published in Age Determination

Watch the stages of decomposition from fresh dead (condition code 2) to advanced decomposition (condition code 4) to skeletal (condition code 5).  These images are all of California sea lions that stranded on the Central California coast.  Check out the stages of decomposition for a porpoise here.

The process of postmortem tissue decomposition is also called AUTOLYSIS ("auto"= self and "lysis"=breakdown). It is caused by a number of factors including ENZYME LEAKAGE, INSECT ACTIVITY and BACTERIAL ACTION.

How do you tell a lesion or injury from damage done by scavenging? Even before an animal hits the beach scavenging by everything from sharks to birds to the neighborhood dog may cause damage to the carcass. While this is nature’s best recycling program, it can be difficult at times to tell normal scavenging from pre-mortem injury or pathological lesions.

How fresh is that carcass? The answer to this question will determine how much information you can potentially get from the animal and what kind of follow up exam you should potentially do. Fresh animals will be candidates for a full necropsy while code 3 or 4 animals may be better suited for a beach necropsy or simple exam.  After reviewing the condition codes be sure to test your knowledge by taking the condition code QUIZ!

The special sensory organs in pinnipeds include the eyes, ears, nose, and vibrissae. Marine mammals, especially pinnipeds, have quite a challenge to overcome because they have to function in air, in water, in bright light, and in low light.

Published in California Sea Lion

The cardiopulmonary system includes the heart and blood vessels, the lymphatic system, nose, nasopharynx, trachea, bronchi and lungs.  These interdependent systems are responsible for picking up and carrying oxygen to the cells of the body and transporting and discarding carbon dioxide.

Published in California Sea Lion

The endocrine system consists of the thyroid and parathyroid glands, pancreas and adrenal glands although other organs are also critical players in the endocrine system as well including the liver, adipose (fat) tissue, the hypothalamus, and pituitary glands.

Published in California Sea Lion

The lymphoreticular system consists of the spleen, lymphnodes, lymphatic vessels, thymus, and bone marrow. The functions of these systems include immune defense, transport of fats throughout the body, and collection and transport of interstitial fluid (the fluid bathing the cells) back to the circulatory system.

Published in California Sea Lion
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