Fish Heath Management Lab 4: Hematology

February 23rd. 2009

Cold Blooded Vertebrates

• Primary site of hematopoiesis is anterior fourth of Primary site of hematopoiesis is anterior fourth of the kidneythe kidney

• Spleen is a accessory area of hematopoiesis as well Spleen is a accessory area of hematopoiesis as well as the site for blood cell destructionas the site for blood cell destruction

• Bone marrow, spleen and lymph nodes serve this Bone marrow, spleen and lymph nodes serve this function warm blooded vertebratesfunction warm blooded vertebrates

• Various types of blood cells in head kidney:Various types of blood cells in head kidney:– ImmatureImmature– MatureMature– Red Blood Cells and White Blood CellsRed Blood Cells and White Blood Cells

Blood Cell Types

• Hemocytoblasts- Stem Cell or blast cells,- Most abundant in hematopoietic 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

• Poly-chromatins- Immature erythrocytes-less elliptical with bluish-gray cytoplasm

Ghost Cells

• Artifact of SamplingArtifact of Sampling– Not definedNot defined– Breakdown and Breakdown and

waste of cellswaste of cells• necrosisnecrosis

Leukocytes

• Immune Response

• Coagulation

• Hard to differentiate

Lymphocytes

• Usually sparse in the blood

• Spherical in shape, 7-10 m

• Eccentrically located spherical nucleus- stains reddish-purple

Neutrophils (Polymorphonuclear Leukocytes)• Only granulocytic

leukocyte present in rainbow trout

• Origin and function of these cells not well understood

• Accounts for 1-9% of total leukocytes

• Average diameter is 9-13 m

• Multi-lobed nucleus (2-5 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

• Normal– Dependent upon species– 25-40%

• Low– Indicates anemia, gill damage, osmoregulation

impairment– <15%

• High– Indicates stress, dehydration, hemoglobin

concentrations – >40%

Lab Procedure

• Take blood from caudal artery

• Use one tube for Blood Smear

• Seal other 2 with CritoSeal 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

K L S

Fish 1

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