The study on the cytology and histochemistry of lymphoid organ spheroids in Penaeus chinensis

Classification of haematopoietic cells and haemocytes in Chinese prawn Fenneropenaeus chinensis

“…A nodular HPT actually termed as lymphoid organ was also described in penaeid shrimp Sicyonia ingentis because of the presence of settled haemocyte in this organ [17]. However, the absence of high mitotic activity suggested that the lymphoid organ could not be considered as a haemocyte source [18,19].…”

Insight into the lymphoid organ of penaeid prawns: A review

“…Diseases associated with lymphoid organ spheroids have been found in Penaeus penicillatus [19], P. monodon [19,30e32], P. merguiensis and Penaeus esculentus [31]. These abnormal cells were also observed in Penaeus vannamei [33,34], P. japonicus [10], Penaeus stylirostris [21] and P. chinensis [25].…”

“…Finally, the subgastric artery branches further to form terminal capillaries, the lumen of the LO tubules [14,24]. Because of this branching pattern, some authors [14,16,18,25] believe that this organ is a part of the vascular system. However, there is evidence suggesting this organ mostly has a filtering function removing foreign materials from the haemolymph [10e12,14] but this does not preclude other as yet unknown functionality.…”

“…In addition, viral infection may cause enlargement of the lymphoid organ. In P. chinensis (body length of 16e17 cm) with tissue changes (lymphoid organ spheroid cells) within the LO probably due to viral infection, the LO size was more than 2 mm in diameter [25]. By weighing the LO in P. stylirostris with an average weight of 5e6 g, the LO was 15 AE 5 mg in the control prawns compared to 110 AE 10 mg in prawns carrying rhabdovirus of penaeid shrimp (RPS).…”

“…The bigger the prawn, the larger the size of the LO. The LO size was less than 2 mm in diameter in Penaeus chinensis with a body length of 12e13 cm [25]. In the ridgeback prawn, Sicyonia ingentis with an average body weight of 14.5 g, the LO had an oval shape and ranged between 1 Â 1.5 mm to 1.5 Â 4 mm in size [18].…”