Journal of Fish Diseases 2014
doi:10.1111/jfd.12245
Short Communication Polycystic liver in flower horn fish, hybrid cichlid H Rahmati-holasoo1, H Ebrahimzadeh Mousavi1, A Vajhi2, S Shokrpoor3, A Tavakkoli2, M A Mirdamadi1 and S Fayyaz4 1 2 3 4
Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran Department of Pathobiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
Keywords: flower horn fish, liver, polycystic. The flower horn fish is from the Cichlid family and appeared in 1996 through selective crossbreeding of three spot cichlid, Cichlasoma trimaculatum (G€ unther), guayas cichlid Cichlasoma festae (Boulenger) and Jingang Blood Parrot. This fish is becoming increasingly popular as a pet, especially in South-East Asia (Lin et al. 2008; Rahmati-holasoo et al. 2010) and Iran. Polycystic liver and kidneys have been found in humans, cats, dogs, pigs and other domestic species (Hadad et al. 1976; Cullen & Brown 2012). In fish, the first polycystic lesions in the kidney of common carp, Cyprinus carpio L., were reported by Plehn (Plehn 1924). Cystic lesions were also reported in ovary of Atlantic Cod, Gadus morhua L. (Wiles 1969), and the spleen of wild brown trout, Salmo trutta L. (Roberts & Macritchie 1971). Smith & Little described the first multiple cystic liver in Pacific electric ray, Torpedo californica Ayres (Smith & Little 1969). Since then, multiple hepatic cysts in Atlantic salmon, Salmo salar L. (Bruno & Ellis 1986), rainbow trout, Oncorhynchus mykiss (Walbaum) (Evensen 2006) and polycystic lesions in the liver of the white sturgeon, Acipenser transmontanus Richardson (Taylor, Smith & Blair 2009) have been reported. Many Correspondence H Rahmati-holasoo, Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, PO Box: 14155-6453, Tehran, Iran (e-mail: [email protected]) Ó 2014 John Wiley & Sons Ltd
1
smaller cysts (100 lm in diameter) were described in the liver of a Pearsei cichlid, Cichlasoma pearsei (Hubbs) (Barlow, Lewbart & Whitney 2000). Polycystic liver in farmed turbot, Scopthalmus maximus (L.), (Jeronimo, Cruz & Saraiva 2011) and goldfish, Carassius auratus (L.), (Rezaie et al. 2012) has also been described. This is the first report of polycystic liver in the flower horn fish. In September 2013, while studying normal radiographs of flower horn fish, a large tissue mass with demarked appearance was seen in the ventral abdomen of a 110 g, year-old male flower horn fish (Fig. 1a). The fish was clinically normal with a normal appetite (Fig. 1b). No parasite or ova were observed in wet smears of skin, gills and faeces. This fish had been obtained as a fry and maintained individually in an aquarium. After 30 days, progressive anorexia, abdominal distention, darkening of skin, decreasing of head protuberance size, and increasing of respiratory rate were observed that lasted for 10 days (Fig. 1c). The fish was anaesthetized in 100 mg L 1 tricaine methane sulphonate (MS-222, Finquelâ, Argent Chemical Laboratories) buffered with 200 mg L 1 sodium bicarbonate. Standard conventional radiographs (using mammography films) were taken in right lateral and dorsoventral projections. A lateral radiograph showed increase in size of soft tissue mass in ventral abdomen and decrease in size of swim bladder (Fig. 1d). Ultrasonography was performed from the left side of the fish. Ultrasonography of visceral organs showed free fluid and an
H Rahmati-holasoo et al. Polycystic liver in flower horn fish
Journal of Fish Diseases 2014
(a)
(b)
(c)
(d)
Figure 1 The flower horn fish. (a) Right lateral radiograph showing a large soft tissue mass in the ventral abdomen with demarked appearance (arrowheads). Normal swim bladder (SB). (b) The flower horn fish with normal colour and head protuberance. (c) Abdominal distention (arrowheads), darkened colour and decreasing of head protuberance size (arrows) compared with Fig. 1b. (d) Right lateral radiograph shows increase in soft tissue mass size in ventral abdomen with demarked appearance (arrowheads) and decrease in swim bladder size (arrows) compared with Fig. 1a.
enlarged liver, containing multiple cysts of various sizes (Fig. 2). The fish died after 1 h, and necropsy was performed under sterile conditions. Aerobic and anaerobic bacterial cultures from multiple internal organs incubated at 25 °C resulted in no growth. At necropsy, free fluid in the abdominal cavity and several cysts (1–4 mm in diameter) in an enlarged and pale liver were observed (Fig. 3). Cysts were delineated by a thin layer and filled
with clear fluid. Other organs exhibited normal appearance. No parasites were observed. For histological purposes, samples of liver, kidney, spleen, gills and gastrointestinal tract were dissected and preserved in 10% buffer formalin, dehydrated and embedded in paraffin, sectioned at 5 lm and stained with haematoxylin–eosin (H&E). Histologically, multiple cysts were seen in the liver (Fig. 4). The cyst walls were composed of squamous epithelium (Fig. 4) and some contained
(a)
(b) Figure 2 Ultrasound image of multiple hypoechoic cysts with different sizes in the liver (black arrows) and the presence of free fluid (white arrows) in the abdominal cavity. Ó 2014 John Wiley & Sons Ltd
2
Figure 3 Gross necropsy images of enlarged and pale liver showing several fluid-filled cysts (arrows). (a & b) lateral and medial view of liver.
Journal of Fish Diseases 2014
Figure 4 Polycystic liver in the flower horn fish. Cysts lined with squamous epithelium (arrow). Severe fatty changes in hepatocytes (arrowhead) (H & E).
Figure 5 Gill of the flower horn fish. Note fusion of lamellae and mild proliferative branchitis (arrowhead) (H & E).
eosinophilic and proteinous fluid (Fig. 4). Numerous sinusoids were dilated by red blood cells. Hyperaemia and haemorrhage were seen in the liver. Severe fatty changes were seen in hepatocytes (Fig. 4). Histological lesions in the gills were hyperplasia of lamellar epithelium, fusion of lamellae and mild proliferative branchitis (Fig. 5). Histologically, gastrointestinal tract, spleen and kidney were normal. Polycystic liver lesions are genetically related in humans (Glawischnig & Bago 2010). Pathogenesis of cystic lesions of animals is usually congenital or parasitic. In many animal species, non-parasitic and congenital hepatic cysts (Krotec et al. 1996; Taylor et al. 2009; Cullen & Brown 2012) have been reported. Reports of cystic conditions in fish are rare (Roberts & Macritchie 1971), and pathogenesis of cystic liver in fish is unknown (Evensen Ó 2014 John Wiley & Sons Ltd
3
H Rahmati-holasoo et al. Polycystic liver in flower horn fish
2006). Hepatic cysts with proteinous and eosinophilic material have been observed in N-nitrosodiethylamine exposed Medaka, Oryzias latipes (Temminck & Schlegel) (Boorman et al. 1997). Formation of hepatic cysts in morpholino-treated zebrafish, Danio rerio (Hamilton) larvae, has also been described (Tietz Bogert et al. 2013). Bruno & Ellis (1986) reported that cysts were surrounded by a connective tissue capsule without epithelial tissue. Taylor et al. (2009) reported that smaller cysts were lined with cuboidal epithelium and surrounded by connective tissue and suggested bile duct origin. In the present report, polycystic lesions were observed only in the liver. Cysts had been surrounded by squamous epithelium that was similar to larger cysts in the liver of white sturgeon, Acipenser transmontanus (Taylor et al. 2009). Ultrasound images and radiographs were unremarkable in diagnosis of hepatic sinusoidal dilatation in a Pearsei cichlid, Cichlasoma pearsei (Barlow et al. 2000). However, radiology and ultrasonography were helpful in diagnosis of polycystic liver in flower horn fish. This is the first published account of radiography and ultrasonography for diagnosis of hepatic polycystic disease in a fish and can be suggested as non-invasive methods for diagnosis of cysts in internal organs of fish. In this study, no histopathological evidence of fibrosis or parasitic involvement at any stage was observed. On the basis of the macroscopic and microscopic characteristics, origin of cysts and cause of this condition remained unknown. However, genetic predisposition appears to be the best explanation for these lesions. Acknowledgements The authors would like to thank Dr. Mohammad Molazem for his assistance in comments on radiographs. References Barlow N.J., Lewbart G.A. & Whitney K.M. (2000) Hepatic sinusoidal dilatation in a Pearsei cichlid, Cichlasoma pearsei. Veterinary Record 146, 23–25. Boorman G.A., Botts S., Bunton T.E., Fournie J.W., Harshbarger J.C., Hawkins W.E., Hinton D.E., Jokinen M.P., Okihiro M.S. & Wolfe M.J. (1997) Diagnostic criteria for degenerative, inflammatory, proliferative nonneoplastic and neoplastic liver lesions in Medaka, Oryzias latipes,: consensus of a National Toxicology Program
Journal of Fish Diseases 2014
Pathology Working Group. Toxicologic Pathology 25, 202– 210. Bruno D.W. & Ellis A.E. (1986) Multiple hepatic cysts in farmed Atlantic salmon, Salmo salar L. Journal of Fish Diseases 9, 79–81. Cullen J.M. & Brown D.L. (2012) Hepatobiliary system and exocrine pancreas. In: Pathological Basis of Veterinary Disease, 5th edn (ed. by J.F. Zachary & M.D. McGavin), pp. 422. Mosby-Elsevier, St Louis, Missouri. Evensen Ø. (2006) Liver. In: Systemic Pathology of Fish: A text and Atlas of Normal Tissues in Teleosts and their Responses in Diseases. 2nd edn (ed. by H.W. Ferguson), pp. 201–216. Scotian Press, Edinburgh. Glawischnig W. & Bago Z. (2010) Polycystic liver disease in senile chamois (Rupicaprae rupicaprae). Journal of Wildlife Diseases 46, 669–672. Hadad A.R., Westbrook K.C., Campbell G.S., Caldwell F.T. & Morris W.D. (1976) Congenital dilatation of the bile ducts. The American Journal of Surgery 132, 799–804. Jeronimo D., Cruz C. & Saraiva A. (2011) Polycystic liver in farmed turbot, Scopthalmus maximus (L.). Journal of Fish Diseases 34, 937–938.
Ó 2014 John Wiley & Sons Ltd
H Rahmati-holasoo et al. Polycystic liver in flower horn fish
Plehn M. (1924) Praktikum der Fischkrankheiten. [Handbook of fish diseases.]. pp. 89–91. Schweizbart, Stuttgart, Germany. Rahmati-holasoo H., Hobbenaghi R., Tukmechi A., Seyrafi R., Homayounimehr A. & Ghavami R. (2010) Lymphocystis in a flower horn fish. Comparative Clinical Pathology 19, 433–435. Rezaie A., Mousavi S.M., Ahmadmoradi E. & Mohammadi F. (2012) Polycystic liver in a goldfish, Carassius auratus (L.). Journal of Fish Diseases 35, 785–787. Roberts R.J. & Macritchie G. (1971) Multiple congenital splenic cysts in wild trout. Journal of Wildlife Diseases 7, 155–156. Smith A.C. & Little H.F. (1969) Liver lesions by hydatid-like cysts in the elasmobranch, the electric ray, Torpedo californica. National Cancer Institute Monograph 31, 251–254. Taylor P., Smith C.E. & Blair M.J. (2009) Polycystic lesions in the liver of the white sturgeon. Journal of Aquatic Animal Health 21, 57–59. Tietz Bogert P.S., Huang B.Q., Gradilone S.A., Masyuk T.V., Moulder G.L., Ekker S.C. & Larusso N.F. (2013) The zebrafish as a model to study polycystic liver disease. Zebrafish 10, 211–217.
Krotec K., Meyer B.S., Freeman W. & Hamir A.N. (1996) Congenital cystic disease of the liver, pancreas, and kidney in a nubian goat, Capra hircus. Veterinary Pathology 33, 708–710.
Wiles M. (1969) Fibrous and cystic lesions in the ovaries of aged Atlantic Cod, Gadus morhua: a preliminary report. Journal of the Fisheries Research Board of Canada 26, 3242–3246.
Lin C.C., Hung S.W., Tu C.Y., Tsou L.T., Shieh M.T., Lin S.L., Liu P.C. & Wang W.S. (2008) Spontaneous stomach lymphoma and liver metastases in flower horn fish, hybrid cichlid. Bulletin of European Association of Fish Pathologists 28, 115–120.
Received: 14 January 2014 Revision received: 12 February 2014 Accepted: 13 February 2014
4
doi:10.1111/jfd.12245
Short Communication Polycystic liver in flower horn fish, hybrid cichlid H Rahmati-holasoo1, H Ebrahimzadeh Mousavi1, A Vajhi2, S Shokrpoor3, A Tavakkoli2, M A Mirdamadi1 and S Fayyaz4 1 2 3 4
Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran Department of Pathobiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
Keywords: flower horn fish, liver, polycystic. The flower horn fish is from the Cichlid family and appeared in 1996 through selective crossbreeding of three spot cichlid, Cichlasoma trimaculatum (G€ unther), guayas cichlid Cichlasoma festae (Boulenger) and Jingang Blood Parrot. This fish is becoming increasingly popular as a pet, especially in South-East Asia (Lin et al. 2008; Rahmati-holasoo et al. 2010) and Iran. Polycystic liver and kidneys have been found in humans, cats, dogs, pigs and other domestic species (Hadad et al. 1976; Cullen & Brown 2012). In fish, the first polycystic lesions in the kidney of common carp, Cyprinus carpio L., were reported by Plehn (Plehn 1924). Cystic lesions were also reported in ovary of Atlantic Cod, Gadus morhua L. (Wiles 1969), and the spleen of wild brown trout, Salmo trutta L. (Roberts & Macritchie 1971). Smith & Little described the first multiple cystic liver in Pacific electric ray, Torpedo californica Ayres (Smith & Little 1969). Since then, multiple hepatic cysts in Atlantic salmon, Salmo salar L. (Bruno & Ellis 1986), rainbow trout, Oncorhynchus mykiss (Walbaum) (Evensen 2006) and polycystic lesions in the liver of the white sturgeon, Acipenser transmontanus Richardson (Taylor, Smith & Blair 2009) have been reported. Many Correspondence H Rahmati-holasoo, Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, PO Box: 14155-6453, Tehran, Iran (e-mail: [email protected]) Ó 2014 John Wiley & Sons Ltd
1
smaller cysts (100 lm in diameter) were described in the liver of a Pearsei cichlid, Cichlasoma pearsei (Hubbs) (Barlow, Lewbart & Whitney 2000). Polycystic liver in farmed turbot, Scopthalmus maximus (L.), (Jeronimo, Cruz & Saraiva 2011) and goldfish, Carassius auratus (L.), (Rezaie et al. 2012) has also been described. This is the first report of polycystic liver in the flower horn fish. In September 2013, while studying normal radiographs of flower horn fish, a large tissue mass with demarked appearance was seen in the ventral abdomen of a 110 g, year-old male flower horn fish (Fig. 1a). The fish was clinically normal with a normal appetite (Fig. 1b). No parasite or ova were observed in wet smears of skin, gills and faeces. This fish had been obtained as a fry and maintained individually in an aquarium. After 30 days, progressive anorexia, abdominal distention, darkening of skin, decreasing of head protuberance size, and increasing of respiratory rate were observed that lasted for 10 days (Fig. 1c). The fish was anaesthetized in 100 mg L 1 tricaine methane sulphonate (MS-222, Finquelâ, Argent Chemical Laboratories) buffered with 200 mg L 1 sodium bicarbonate. Standard conventional radiographs (using mammography films) were taken in right lateral and dorsoventral projections. A lateral radiograph showed increase in size of soft tissue mass in ventral abdomen and decrease in size of swim bladder (Fig. 1d). Ultrasonography was performed from the left side of the fish. Ultrasonography of visceral organs showed free fluid and an
H Rahmati-holasoo et al. Polycystic liver in flower horn fish
Journal of Fish Diseases 2014
(a)
(b)
(c)
(d)
Figure 1 The flower horn fish. (a) Right lateral radiograph showing a large soft tissue mass in the ventral abdomen with demarked appearance (arrowheads). Normal swim bladder (SB). (b) The flower horn fish with normal colour and head protuberance. (c) Abdominal distention (arrowheads), darkened colour and decreasing of head protuberance size (arrows) compared with Fig. 1b. (d) Right lateral radiograph shows increase in soft tissue mass size in ventral abdomen with demarked appearance (arrowheads) and decrease in swim bladder size (arrows) compared with Fig. 1a.
enlarged liver, containing multiple cysts of various sizes (Fig. 2). The fish died after 1 h, and necropsy was performed under sterile conditions. Aerobic and anaerobic bacterial cultures from multiple internal organs incubated at 25 °C resulted in no growth. At necropsy, free fluid in the abdominal cavity and several cysts (1–4 mm in diameter) in an enlarged and pale liver were observed (Fig. 3). Cysts were delineated by a thin layer and filled
with clear fluid. Other organs exhibited normal appearance. No parasites were observed. For histological purposes, samples of liver, kidney, spleen, gills and gastrointestinal tract were dissected and preserved in 10% buffer formalin, dehydrated and embedded in paraffin, sectioned at 5 lm and stained with haematoxylin–eosin (H&E). Histologically, multiple cysts were seen in the liver (Fig. 4). The cyst walls were composed of squamous epithelium (Fig. 4) and some contained
(a)
(b) Figure 2 Ultrasound image of multiple hypoechoic cysts with different sizes in the liver (black arrows) and the presence of free fluid (white arrows) in the abdominal cavity. Ó 2014 John Wiley & Sons Ltd
2
Figure 3 Gross necropsy images of enlarged and pale liver showing several fluid-filled cysts (arrows). (a & b) lateral and medial view of liver.
Journal of Fish Diseases 2014
Figure 4 Polycystic liver in the flower horn fish. Cysts lined with squamous epithelium (arrow). Severe fatty changes in hepatocytes (arrowhead) (H & E).
Figure 5 Gill of the flower horn fish. Note fusion of lamellae and mild proliferative branchitis (arrowhead) (H & E).
eosinophilic and proteinous fluid (Fig. 4). Numerous sinusoids were dilated by red blood cells. Hyperaemia and haemorrhage were seen in the liver. Severe fatty changes were seen in hepatocytes (Fig. 4). Histological lesions in the gills were hyperplasia of lamellar epithelium, fusion of lamellae and mild proliferative branchitis (Fig. 5). Histologically, gastrointestinal tract, spleen and kidney were normal. Polycystic liver lesions are genetically related in humans (Glawischnig & Bago 2010). Pathogenesis of cystic lesions of animals is usually congenital or parasitic. In many animal species, non-parasitic and congenital hepatic cysts (Krotec et al. 1996; Taylor et al. 2009; Cullen & Brown 2012) have been reported. Reports of cystic conditions in fish are rare (Roberts & Macritchie 1971), and pathogenesis of cystic liver in fish is unknown (Evensen Ó 2014 John Wiley & Sons Ltd
3
H Rahmati-holasoo et al. Polycystic liver in flower horn fish
2006). Hepatic cysts with proteinous and eosinophilic material have been observed in N-nitrosodiethylamine exposed Medaka, Oryzias latipes (Temminck & Schlegel) (Boorman et al. 1997). Formation of hepatic cysts in morpholino-treated zebrafish, Danio rerio (Hamilton) larvae, has also been described (Tietz Bogert et al. 2013). Bruno & Ellis (1986) reported that cysts were surrounded by a connective tissue capsule without epithelial tissue. Taylor et al. (2009) reported that smaller cysts were lined with cuboidal epithelium and surrounded by connective tissue and suggested bile duct origin. In the present report, polycystic lesions were observed only in the liver. Cysts had been surrounded by squamous epithelium that was similar to larger cysts in the liver of white sturgeon, Acipenser transmontanus (Taylor et al. 2009). Ultrasound images and radiographs were unremarkable in diagnosis of hepatic sinusoidal dilatation in a Pearsei cichlid, Cichlasoma pearsei (Barlow et al. 2000). However, radiology and ultrasonography were helpful in diagnosis of polycystic liver in flower horn fish. This is the first published account of radiography and ultrasonography for diagnosis of hepatic polycystic disease in a fish and can be suggested as non-invasive methods for diagnosis of cysts in internal organs of fish. In this study, no histopathological evidence of fibrosis or parasitic involvement at any stage was observed. On the basis of the macroscopic and microscopic characteristics, origin of cysts and cause of this condition remained unknown. However, genetic predisposition appears to be the best explanation for these lesions. Acknowledgements The authors would like to thank Dr. Mohammad Molazem for his assistance in comments on radiographs. References Barlow N.J., Lewbart G.A. & Whitney K.M. (2000) Hepatic sinusoidal dilatation in a Pearsei cichlid, Cichlasoma pearsei. Veterinary Record 146, 23–25. Boorman G.A., Botts S., Bunton T.E., Fournie J.W., Harshbarger J.C., Hawkins W.E., Hinton D.E., Jokinen M.P., Okihiro M.S. & Wolfe M.J. (1997) Diagnostic criteria for degenerative, inflammatory, proliferative nonneoplastic and neoplastic liver lesions in Medaka, Oryzias latipes,: consensus of a National Toxicology Program
Journal of Fish Diseases 2014
Pathology Working Group. Toxicologic Pathology 25, 202– 210. Bruno D.W. & Ellis A.E. (1986) Multiple hepatic cysts in farmed Atlantic salmon, Salmo salar L. Journal of Fish Diseases 9, 79–81. Cullen J.M. & Brown D.L. (2012) Hepatobiliary system and exocrine pancreas. In: Pathological Basis of Veterinary Disease, 5th edn (ed. by J.F. Zachary & M.D. McGavin), pp. 422. Mosby-Elsevier, St Louis, Missouri. Evensen Ø. (2006) Liver. In: Systemic Pathology of Fish: A text and Atlas of Normal Tissues in Teleosts and their Responses in Diseases. 2nd edn (ed. by H.W. Ferguson), pp. 201–216. Scotian Press, Edinburgh. Glawischnig W. & Bago Z. (2010) Polycystic liver disease in senile chamois (Rupicaprae rupicaprae). Journal of Wildlife Diseases 46, 669–672. Hadad A.R., Westbrook K.C., Campbell G.S., Caldwell F.T. & Morris W.D. (1976) Congenital dilatation of the bile ducts. The American Journal of Surgery 132, 799–804. Jeronimo D., Cruz C. & Saraiva A. (2011) Polycystic liver in farmed turbot, Scopthalmus maximus (L.). Journal of Fish Diseases 34, 937–938.
Ó 2014 John Wiley & Sons Ltd
H Rahmati-holasoo et al. Polycystic liver in flower horn fish
Plehn M. (1924) Praktikum der Fischkrankheiten. [Handbook of fish diseases.]. pp. 89–91. Schweizbart, Stuttgart, Germany. Rahmati-holasoo H., Hobbenaghi R., Tukmechi A., Seyrafi R., Homayounimehr A. & Ghavami R. (2010) Lymphocystis in a flower horn fish. Comparative Clinical Pathology 19, 433–435. Rezaie A., Mousavi S.M., Ahmadmoradi E. & Mohammadi F. (2012) Polycystic liver in a goldfish, Carassius auratus (L.). Journal of Fish Diseases 35, 785–787. Roberts R.J. & Macritchie G. (1971) Multiple congenital splenic cysts in wild trout. Journal of Wildlife Diseases 7, 155–156. Smith A.C. & Little H.F. (1969) Liver lesions by hydatid-like cysts in the elasmobranch, the electric ray, Torpedo californica. National Cancer Institute Monograph 31, 251–254. Taylor P., Smith C.E. & Blair M.J. (2009) Polycystic lesions in the liver of the white sturgeon. Journal of Aquatic Animal Health 21, 57–59. Tietz Bogert P.S., Huang B.Q., Gradilone S.A., Masyuk T.V., Moulder G.L., Ekker S.C. & Larusso N.F. (2013) The zebrafish as a model to study polycystic liver disease. Zebrafish 10, 211–217.
Krotec K., Meyer B.S., Freeman W. & Hamir A.N. (1996) Congenital cystic disease of the liver, pancreas, and kidney in a nubian goat, Capra hircus. Veterinary Pathology 33, 708–710.
Wiles M. (1969) Fibrous and cystic lesions in the ovaries of aged Atlantic Cod, Gadus morhua: a preliminary report. Journal of the Fisheries Research Board of Canada 26, 3242–3246.
Lin C.C., Hung S.W., Tu C.Y., Tsou L.T., Shieh M.T., Lin S.L., Liu P.C. & Wang W.S. (2008) Spontaneous stomach lymphoma and liver metastases in flower horn fish, hybrid cichlid. Bulletin of European Association of Fish Pathologists 28, 115–120.
Received: 14 January 2014 Revision received: 12 February 2014 Accepted: 13 February 2014
4
