Hematology Fish Health Management Cold Blooded Vertebrates Primary

Hematology Fish Health Management

Cold Blooded Vertebrates • Primary site of hematopoiesis is anterior fourth of the kidney • Spleen is a accessory area of hematopoiesis as well as the site for blood cell destruction • Bone marrow, spleen and lymph nodes serve this function warm blooded vertebrates • Various types of blood cells in head kidney: - Immmature - Mature - Red Blood Cells and White Blood Cells

Blood Cell Types • Hemocytoblast- Stem Cell or blast cells, - Most abundant in hemopoetic tissue of kidney, rare in blood • Erythrocytes- Red Blood Cells - Carries Oxygen • Leukocytes- White Blood Cells - Blood Clotting - Phagocytosis - Inflammation Response

Erythrocytes • Primary Function: Oxygen transport • Elongated elliptical cell: 13 -16 m long by 7 -10 wide m • Nucleus centrally located, elliptical in shape • Polychromatins- Immature erythrocytesless elliptical with blueish-gray cytoplasm

Ghost Cells • Artifact of Sampling

Leukocytes • Immune Response • Coagulation • Hard to differentiate

Lymphocytes • Usually sparse in red blood cells • Spherical in shape, 710 m • Eccentrically located spherical nucleus- stains reddish-purple

Neutrophils (Polymorphonuclear Leukocytes) • Only granulocytic leukocyte present in rainbow trout • Origin and function of theses cells not well understood • Accounts for 1 -9% of total leukocytes • Average diameter is 9 -13 m • Multi-lobuated nucleus (25 lobes)

Thrombocytes • Occur in varying shapes and size: elongated, spiked, fusiform, and spheroid. • Elongated - 5 -8 m long • Spiked – streaked cytoplasm on one end • Fusiform- streaked cytoplasm on both ends • Spheroid- dense nuclei, little or no cytoplasm

Monocytes and Macrophages • Monocytes- large 9 -25 m • Indistinguishable from Macrophages once in tissue • Cytoplasm often has granules and a large nucleus • Macrophages not usually seen in blood

Kidney Imprint • Various states of hematopoiesis

Blood Sampling Non-Lethal • Mouth Catheterization • Caudal Artery • Heart Lethal • Sever Caudal Peduncle • Sever Gill

Blood Assessment • Three Indexes: – Red Blood Cell Abundance • Hemoglobin • Hematocrit - Ratio of Packed RBC’s to total blood volume • Variations in reading can be caused by species, sex, age, temperature, clotting, water quality, season

Hematocrit Readings • Low – Indicates anemia, gill damage, osmoregulation impairment • High – Indicates stress, dehydration, hemoglobin concentrations

Lab Procedure • • • Take blood from caudal artery Use one tube for Blood Smear Seal other 2 with Crito. Seal at vacant end Measure % of both Tissue imprints

Tissue Imprints • Cut a small piece of Tissue • Using forceps, create imprints by touching tissue to slide in succession Fish 1 K L S

Stain using Diff Quick • Fix slides in Solution A (Methyl Alcohol) for 10 min • Dip slides in Solution B 25 times • Dip slides in Solution C 25 times • Wash with DDI water. Dry and examine the slides.