Spirocamallanus cricotus (Nematoda): isoelectric focusing and spectrophotometric characterization of its hemoglobin and that of its piscine host, Micropogonias undulatus

The hemoglobins of Spirocamallanus cricotus, a reddish-colored, camallanid nematode, and its Atlantic croacker fish host, Micropogonias undulatus, were characterized with spectrophotometry and isoelectric focusing. Hemoglobin from female parasites' perienteric fluid and homogenized male parasites gave Spectrophotometric peaks at 412, 539, and 575 nm, whereas female worms drained of perienteric fluid and homogenized differed by having a Soret peak of 408 nm. Changing the ionic strength of the buffer from 0.1 to 0.01 M shifted the Soret peak to 406 nm for the female parasites' perienteric fluid and ground male parasites and 404 nm for homogenized female parasites. In all cases, the β band had a higher absorption than the α band suggesting a high O₂ affinity for the parasite hemoglobin. Host hemoglobin had peaks of 406, 437, and 577 nm. Isoelectric focusing not only confirmed the Spectrophotometric evidence that host and parasite hemoglobins differed, but also showed that the parasite's analyzed hemoglobin fractions differed from one another by having different isoelectric points.