ABSTRACT
Insects are increasingly common in households, zoological collections, research, and food industries. Increased knowledge of insect health parameters is necessary to ensure proper welfare. The study goal was to develop a hemolymph collection technique and report hemolymph serum biochemical parameters for the thorny devil stick insect (Eurycantha calcarata). Clinically healthy adult stick insects (5 males and 14 females, 15.1-24.7 g) were enrolled. Four collection techniques were evaluated. Hemolymph collection was unsuccessful in males, but was successful in females by using a single technique. The insect was manually restrained in an elevated position and an 18-ga × 2.54-cm needle was used to puncture the membrane just caudal to the third pair of legs. With the puncture site directed ventrally, ≤1 ml of hemolymph was collected via gravity and allowed to visibly clot. The sample was then centrifuged, and the serum was separated. Serum samples were individually analyzed (Avian/Reptilian Profile Plus, VetScan VS2, Abaxis, Inc, Union City, CA 94587, USA). Fourteen samples (0.2-1.0 ml) were collected from 14 females. Median (minimum-maximum) parameters included the following: aspartate aminotransferase 12 (0-45) U/L, creatinine kinase 25 (0-76) U/L, uric acid 7.5 (3.1-13.7) mg/dl, glucose 12 (8-22) mg/dl, calcium 18.6 (17.2-19.4) mg/dl, phosphorus 15.0 (n = 1) or >30.0 (n = 13) mg/dL, total protein 2.7 (1.6-2.9) g/dL, albumin 0.9 (0.2-1.2) g/dL, globulin 1.7 (1.6-1.8) g/dL (n = 6) or not quantified (n = 8), potassium 10.6 (9.0-11.8) mmol/L, sodium < 100 mmol/L, and bile acids 0 lmol/L. This is the first report of biochemistry parameters in clinically healthy female stick insects. Larger sample sizes are needed to establish statistically valid reference ranges. Hemolymph collection techniques for male stick insects warrant further investigation.
Subject(s)
Hemolymph , Serum , Animals , Female , Male , Albumins , Sodium , Reference Values , InsectaABSTRACT
The thorny devil stick insect (Eurycantha calcarata) is a common invertebrate maintained under human care. Blood (hemolymph) transfusions are a widely used therapeutic tool in other species, but investigation in terrestrial arthropods remains scarce. Study objectives were development and evaluation of a serum transfusion process in the thorny devil stick insect. Twenty-five clinically healthy adult insects (9.9-23.0 g) were enrolled and baseline body weights were collected. Hemolymph collection was not successful in males, thus, all were recipient only (n = 12, MR). Females were divided into donor (n = 4, FD) or donor and recipient (n = 9, FDR) groups. Females were manually restrained and up to 1 mL of hemolymph was collected from the abdominal segment caudal to the proximal hindlimb using an 18 g hypodermic needle and passive collection via gravity. Hemolymph was quantified, centrifuged, and the serum separated. Insects were then injected superficially at the lateral aspect of the abdomen with 0.01 mL/g FD serum (MR), lactated Ringer's solution (LRS) equal to collected hemolymph volume (FD), or a combination of FDR serum and LRS equal to collected hemolymph volume (FDR). Response to stimulation, surface temperature, and righting reflex and mortality were serially assessed for up to 24 h and 7 days, respectively, following injection. In FD, median (range) injected LRS dose was 0.04 (0.03-0.06) mL/g. In FDR, median (range) injected serum, LRS, and combined serum and LRS dose was 0.03 (0.02-0.04), 0.01 (0-0.04), and 0.04 (0.02-0.06) mL/g, respectively. A mild temperature increase (maximum +2.9°C) (MR n = 10, FD n = 3, FDR n = 8) and delayed righting reflex (MR n = 4, FD n = 3, FDR n = 7) occurred in a subset of insects following injection. Two deaths occurred at 2 min (n = 1, FDR) and 96 h (n = 1, FD) post-injection. This is the first report of serum transfusions in thorny devil stick insects, and while largely successful, minor to severe transfusion reactions may occur.