Zoological Studies

Vol. 46 No. 2, 2007

Identification of a Female-Specific Hemocyanin in the Mud Crab, Scylla olivacea (Crustacea: Portunidae)

Hong-Yu Chen1, Shih-Hu Ho2, Tzyy-Ing Chen2,3, Keryea Soong2, I-Ming Chen1, and Jin-Hua Cheng2,3,*

1Institute of Marine Resources, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
2Institute of Marine Biology, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
3Biotech Division, Fisheries Research Institute, Tungkang, Pingtung 928, Taiwan

Hong-Yu Chen, Shih-Hu Ho, Tzyy-Ing Chen, Keryea Soong, I-Ming Chen, and Jin-Hua Cheng (2007) Copper-containing proteins, hemocyanins, are respiratory proteins of crustacean decapods. In this paper, a novel female-specific hemocyanin (FSH) in the mud crab, Scylla olivacea (Crustacea: Portunidae), is reported. FSH occurs in the hemolymph of adult females with maturing ovaries, but not in the hemolymph of juveniles of either sex or in adult males. FSH was purified from the hemolymph of females with maturing ovaries by liquid chromatography. Further analysis revealed that FSH is a carbohydrate-rich protein; no cross-immune reaction was found between FSH and vitellin; furthermore, it does not resemble vitelloprotein molecules. It has characteristics in common with other better-known hemocyanins, such as its copper content and oxygen-binding ability. The P50 of FSH is 28.3 mmHg O2, and its oxygen saturation point is 152 mmHg. From evidence of its oxygen-binding ability, it is certain that FSH is a unique hemocyanin of female crabs with maturing ovaries, and its functions are supposedly correlated with reproduction in female crabs.

Key words: Female-specific hemocyanin, Vitellin, Vitellogenin, Mud crab, Scylla olivacea.

*Correspondence: Tel: 886-8-8324121 ext. 205. Fax: 886-8-8320234. E-mail:chengjh@mail.nsysu.edu.tw