Comparative hematology of wild Anguilliformes (Muraena helena, L. 1758, Conger conger, L. 1758 and Anguilla anguilla L. 1758)

in Animal Biology
Restricted Access
Get Access to Full Text
Rent on DeepDyve

Have an Access Token?

Enter your access token to activate and access content online.

Please login and go to your personal user account to enter your access token.


Have Institutional Access?

Access content through your institution. Any other coaching guidance?


The objective of this study was to compare circulating blood cell counts and morphology of three eel species: Muraena helena (moray), Conger conger (European conger) and Anguilla anguilla (European common eel). Moray and conger were collected from the Adriatic Sea at the Elaphite Islands near Dubrovnik, Croatia; common eels were collected in the Neretva River, Croatia. Hematological comparison was conducted using Natt-Harrick’s and May-Grünwald Giemsa staining methods. The hematocrit of moray and conger were similar, while common eel had higher values by 60%. Manual cell count showed that common eel had the highest erythrocyte count. Conger had a higher erythrocyte count than moray, with a higher percentage of proerythrocytes and senescent erythrocytes compared to moray and common eel. The leukocyte count was similar in common eel and moray and slightly lower in conger. The thrombocyte count was highest in conger and lowest in moray. In all three species, the neutrophil (heterophil) nuclei appeared as either circular or bi-lobed. Moray had the highest neutrophil (heterophil) percentage and a subtype with intensively basophilic cytoplasm appearing in a similar percentage as the normal type. In common eel, neutrophils (heterophils) were the only detected granulocytes. Basophils were detected in conger eels. Eosinophils were not detected in any of the sampled fish. The size of all cell types in moray was slightly larger than in other two species. In conclusion, our findings reveal major differences in the cell count and diversity in cell subtypes between three kin species of eels.

Comparative hematology of wild Anguilliformes (Muraena helena, L. 1758, Conger conger, L. 1758 and Anguilla anguilla L. 1758)

in Animal Biology



AinsworthA.J. (1992) Fish granulocytes, morphology, distribution, and function. Ann. Rev. Fish Dis.2123-148.

AndersonD.P.ZeemanM.G. (1995) Immunotoxicology in fish. In: RandG.M. (Ed.) Fundamentals of Aquatic Toxicology pp.  371-404. Taylor and FrancisWashington.

ArikanH.Ipagut-KeskinN.A.ÇevikE.ErişmişU.C. (2010) A study on the blood cells of the fire-bellied toad, Bombina bombina L. (Anura: Bombinatoridae). Anim. Biol.6061-68.

BartoliP.GibsonD.I. (2007) The status of Lecithochirium grandiporum (Rudolphi, 1819) (Digenea: Hemiuridae), a rarely reported and poorly known species from the Mediterranean moray eel Muraena helena L. in the Western Mediterranean. Syst. Parasit.68183-194.

CampbellT.MurruF. (1990) An introduction to fish hematology. Comp. Cont. Educ. Vet. Sci.12525-533.

CampbellT.EllisW. (2007) Avian and Exotic Animal Hematology and Cytology. 3rd ed. Blackwell PublishingAmes, Iowa, USA.

CannonM.S.MollenhauerH.H.EurellT.E.LewisD.H.CannonA.M. (1980) An ultrastructural study of the leucocytes of the channel catfish, Ictalurus punctatus. J. Morph.1641-20.

CerraM.C.CanonacoM.TotaB. (1992) A quantitative autoradiographic study of 125I atrial natriuretic factor in the heart of a teleost fish (Conger conger). J. Exp. Zool.263215-219.

ClaussT.M.DoveA.D.M.ArnoldJ.E. (2008) Hematologic disorders of fish, Veterinary clinics of North America. Ex. Anim. Pract.11445-462.

DavisA.K.MilanovichJ.R.DeVoreJ.L.MaerzJ.C. (2009) An investigation of factors influencing erythrocyte morphology of red-backed salamanders (Plethodon cinereus). Anim. Biol.59201-220.

DoveA.D.M.ArnoldJ.ClaussT.M. (2010) Blood cells and serum chemistry in the world’s largest fish: the whale shark Rhincodon typus. Aquat. Biol.9177-183.

ÐikićD.SkaramucaD.LisičićD.Matić-SkokoS.TutmanP.BenkovićV.Horvat-KneževićA.GavrilovićA.SkaramucaB. (2010) Blood cell count of Muraena helena L. 1758 from Eastern Adriatic Sea near Dubrovnik Croatia. Rapport de la Commission Internationale pour l’Exploration Scientifique de la mer Méditerranée (CIESM Congress Proceedings) 39 Frederic Briand (Ed.) Venice. CIESM 140.

ÐikićD.LisičićD.SkaramucaD.Matić-SkokoS.TutmanP.BenkovićV.Horvat-KneževićA.GavrilovićA.SkaramucaB. (2011) Blood cellular components in wild caught Muraena helena, L. 1758. Cybium35149-156.

EllisA.E. (1977) The leucocytes of fish, a review. J. Fish Biol.11453-491.

EricksonT.Vanden HoekT.L.KuritzaA.LeikenJ.B. (1992) The emergency management of moray eel bites. Ann. Emerg. Med.21212-216.

FilhoD.W.ElbeG.J.CancerG.CaprarioF.X.DafneA.L. (1992) Comparative hematology in marine fish. Comp. Biochem. Phys. A102311-321.

FISHBASE – Muraena helena info 2012. summary

Francis-FloydR.ArdeltT.C.AndrewM.RothL.ReedP.RoseE. (1991) Hematologic parameters of Green Moray Eel (Gymnothorax funebris). WSAV Proceedings.

van GinnekenV.J.T.BallieuxT.B.WillemzeR.ColdenhoffK.LentjesE. (2005) Hematology patterns of migrating European Anguilla and the role of EVEX virus. Comp. Biochem. Phys. C14097-102.

van GinnekenV.J.T.MaesG.E. (2005) The European eel (Anguilla anguilla, Linnaeus), its lifecycle, evolution and reproduction, a literature review. Rev. Fish. Biol. Fisheries15367-398. DOI 10.1007/s11160-006-0005-8.

GuijarroA.I.Lopez-PatinoM.A.PinillosM.IsornaE.De PedroN. (2003) Seasonal changes in hematology and metabolic resources in the tench. J. Fish Biol.62803-815.

HendrickM.DinapoliA.CammarataP.PincusS. (1986) Purification of carp putative eosinophils on metrizamide gradients. J. Fish Biol.2947-51.

HineP.M. (1992) The granulocytes of fish. Fish Shell. Imm.279-98.

HrubecT.C.SmithS.A. (2000) Hematology of fish. In: FeldmanB.F.ZinklJ.G.JainN.C. (Eds.) Schlam’s Veterinary Hematology pp.  1120-1125. Lippincott Williams and Wilkins. Int.

HyderS.L.CayerM.L.PetteyC.L. (1983) Cell types in peripheral blood of the nurse shark; an approach to structure and function. Tiss. Cell.15437-455.

JardasI. (1996) Jadranska ihtiofauna (Adriatic ichthyofauna) p.  535. Školska knjigaZagreb (in Croatian).

JohanssonM.L.DaveG.LarssonA.LewanderK.LidmanU. (1974) Metabolic and hematological studies on the yellow and silver phases of the European eel, Anguilla anguilla L. I2 Hematology. Comp. Biochem. Phys. B47593-594.

KakutaI.NakaiT. (1992) Blood changes in Japanese Anguilla, Anguilla japonica, experimentally infected with typical or atypical Aeromonas salmonicida. Comp. Biochem. Phys. A103151-155.

KapoorB.G.KhannaB. (2004) Ichthyology Handbook p.  964. Narosa Publishing House New Delhi & Springer VerlagBerlin, Heidelberg, New York.

KusudaR.IkedaY. (1987) Studies on classification of eel leucocytes. Nippon Suisan Gakkaishi-Bull. Japan Soc. Fish Sci.53205-209.

LarssonA.Johansson-SjobeckM.L.FangerR. (1976) Comparative study of some haematological and biochemical blood parameters in the fishes from Skagerrak. J. Fish Biol.9425-440.

LupoC.ChieffiG. (1963) Oestrogens and progesterone in ovaries of the marine teleost Conger conger. Nature9197596.

Matić-SkokoS.TutmanP.MarčeljaE.SkaramucaD.ÐikićD.LisičićD.SkaramucaB. (2010) Feeding habits and trophic status of Mediterranean moray eel Muraena helena L. 1758 in the Adriatic Sea – a preliminary approach. Rapport de la Commission Internationale pour l’Exploration Scientifique de la mer Méditerranée (CIESM Congress Proceedings) 39 Frederic Briand (Ed.) Venice. CIESM 122.

Matić-SkokoS.TutmanP.PetrićM.SkaramucaD.ÐikićD.LisičićD.SkaramucaB. (2011) Mediterranean moray eel, Muraena helena (Pisces, Muraenidae), biological indices for life history. Aquat. Biol.13275-284.

MehtaR.S.WainwrightP.C. (2007) Raptorial jaws in the throat help moray eel swallow large prey. Nature44979-82.

Orecka-GrabidaT. (1986) Haematological, clinical and anatomical pathology of the European eel (Anguilla anguilla (L.)) from polluted waters of northwestern Poland. A. Icht. et Piscat.16107-125.

ParishN.WrathmellA.HartS.HarrisJ.E. (1986) The leucocytes of the elasmobranch Scyliorhinus canicula L. – a morphological study. J. Fish Biol.28545-561.

PastoretP.P.GriebelP.BazinH.GovaertsA. (1998) Immunology of fishes. In: Handbook of Vertebrate Immunology pp.  3-62. Academic PressSan Diego.

PavlidisM.FutterW.C.KathariosP.DivanachP. (2007) Blood cell profile of six Mediterranean mariculture fish species. J. App. Icht.2370-73.

PellegriniM.GardinaB.OlianasA.SannaM.T.DeianaA.M.SalvadoriS. (1995) Structure/function relationships in the hemoglobin components from moray (Muraena helena). Eu. J. Biochem.234431-436.

PellegriniM.GiardinaB.VerdeC.CarratoreV.OlianasA.SollaiL.SannaM.T.CastagnolaM.Di PriscoG. (2003) Structural-functional characterization of the cathodic haemoglobin of the conger eel Conger conger, molecular modelling study of an additional phosphate-binding site. Biochem. J.372679-686.

PichiriG.NiedduM.MezzanotteR.ConiP.P.SalvadoriS. (1995) The molecular characterization of the genome of Muraena helena L. Isolation and hybridization of two MboI-restricted DNA fractions. Genome38809-813.

PichiriG.ConiP.DeianaA.M.NiedduM.MezzanotteR. (2000) On the variability of MboI repeated sequences and 5S rDNA in Muraena helena and Gymnothorax unicolor (Anguilliformes, Muraenidae). Chromosome Res.8443-445.

PonsenS.NarkkongN.A.PamokS.AengwanichW. (2009) Comparative hematological values, morphometric and morphological observation of the blood cell in captured and culture Asian eel, Monopterus albus. Am. J. An. Vet. Sci.432-36.

Ranzani-PaivaM.J.T.RodriguesE.L.VeigaM.L. (2003) Differential leukocyte counts in “Dourado”, Salminus Maxillosus Valenciennes, 1840, from the Mogi-Guaçuriver, Pirassununga. Braz. J. Biol.63517-525.

RiđanovićL.RiđanovićS.JuricaD.SpasojevićP. (2010) Evaluation of water temperature and dissolved oxygen regimes in river Neretva. BALWOIS 2010. 25-29 May-Ohrid Republic of Macedonia.

ReavillD.RobertsH. (2007) Diagnostic cytology of fish. Vet. Clin. Exot. Anim.10207-234.

RonchettiE.SalvadoriS.DeianaA.M. (1995) Genome size and AT content in Anguilliformes. Eu. J. Histochem.39259-264.

ŞahanA.AltunT.ÇevikF.CengizlerI.NevşatE.GençE. (2007) Comparative study of some haematological parameters in European eel (Anguilla anguilla L. (1758)) caught from different regions of the Ceyhan River (Adana, Turkey). E.U. J. Fisher. & Aquat Sci.24167-171.

SantosM.J.GibsonD.I. (2002) Morphological features of Prosorhynchus crucibulum and P. aculeatus (Digenea, Bucephalidae), intestinal parasites of Conger conger (Pisces, Congridae), elucidated by scanning electron microscopy. Folia Parasitol. (Praha)4996-102.

SasalP.MorandS.GueganJ.F. (1997) Determinants of parasite species richness in Mediterranean marine fishes. Mar. Ecol. Prog. Ser.14961-71.

SbaihiM.Fouchereau-PeronM.MeunierF.ElieP.MayerI.Burzawa-GerardE.VidalB.DufourS. (2001) Reproductive biology of conger eel from the south coast of Brittany, France and comparison with the European eel. J. Fish Biol.59302-318.

ShigdarS.HarfordA.WardA.C. (2009) Cytochemical characterisation of the leucocytes and thrombocytes from Murray cod (Maccullochella peelii peelii, Mitchell). Fish Shell. Imm.26731-736.

StarkH.SchusterS. (2012) Comparison of various approaches to calculating the optimal hematocrit in vertebrates. J. Appl. press DOI 10.1152/japplphysiol.00369.2012

SuzukiY.IidaT. (1992) Fish granulocytes in the process of inflammation. Ann. Rev. Fish Dis.2149-160.

Tavares-DiasM. (2006) Cytochemical method for staining fish basophils. J. Fish Biol.69312-317.

ThrallM.A.BakerD.C.LassenE.D. (2004) Hematology of fish. In: TroyD.B. (Ed.) Veterinary Hematology and Clinical Chemistry. Lippincott Williams & WilkinsPhiladelphia, Pennsylvania, USA.

ThuvanderA.NorrgrenL.FossumC. (1987) Phagocytic cells in blood from rainbow trout, Salmo gairdneri (Richardson), characterized by flow cytometry and electron microscopy. J. Fish Biol.31197-208.

ToewsD.P.HoletonG.F.HeislerN. (1983) Regulation of the acid-base status during environmental hypercapnia in the marine teleost fish Conger conger. J. Exp. Biol.1079-20.


  • View in gallery

    Leukocytes of moray (Muraena helena), conger (Conger conger) and European common eel (Anguilla anguilla) stained by May Grunwald Giemsa stain. (A) Muraena helena neutrophil (heterophil). (B) Muraena helena normal neutrophil (heterophil) (left cell) and neutrophil (heterophil) with intensively basophilic cytoplasm (IBG cell, right cell). (C) Muraena helena neutrophil (heterophil) with bi-lobed nucleus. (D) Muraena helena monocyte. (E) Muraena helena lymphocyte (right cell) compared to round thrombocyte (left cell). (F) Conger conger neutrophil (heterophil). (G) Conger conger basophile. (H) Conger conger neutrophil with bi-lobed nucleus. (I) Conger conger monocyte. (J) Conger conger lymphocyte. (K) Anguilla anguilla neutrophil (heterophil). (L) Anguilla anguilla normal neutrophil (heterophil) (left cell) and neutrophil (heterophil) with slightly basophilic cytoplasm (right cell). (M) Anguilla anguilla neutrophil (heterophil) with bi-lobed nucleus. (N) Anguilla anguilla monocyte. (O) Anguilla anguilla lymphocyte. Magnification: immersion, 1000×.


Content Metrics

Content Metrics

All Time Past Year Past 30 Days
Abstract Views 51 51 9
Full Text Views 80 80 52
PDF Downloads 11 11 5
EPUB Downloads 5 5 0