Food intake, survival, and immunity of Nibea albiflora to Cryptocaryon
Received: 10 November 2017 /Accepted: 10 May 2018 /Published online: 30 May 2018
Springer-Verlag GmbH Germany, part of Springer Nature 2018
Cultured Nibea albiflora rarely die from cryptocaryoniasis. To explore the resistance of N. albiflora against the invasion of
Cryptocaryon irritans,inthisstudy,40gN. albiflora was artificially infected with C. irritans at a median lethal concentration
(2050 theronts/g fish). The food intake, survival, relative infection intensity, and immobilization titer variation of serum and
mucus at different time points after the infection were compared. Results showed that the ingestion of N. albiflora could be
resumed only 1 day after feed deprivation by the disease, which indicated the quick resilience of N. albiflora. N. albiflora did not
die out even if it was cultured continually for up to 15 days at 27 °C in a culture tank with a large quantity of C. irritans tomonts. It
was because that, without any exterior force, N. albiflora could block the C. irritans cell proliferation, and then the pathogens
disappear gradually. In vitro immobilization titer test results confirmed that the serum and mucus could directly eradicate C.
Keywords Nibea albiflora
Cryptocaryon irritans parasitizes on the body surface of fish,
such as in the epithelial tissue of the skin, gill, and fin. In the
case of intensive culture of marine fish, the parasites can lead
to the massive acute death of the host fish. The primary cause
of death is that the damage C. irritans creates in the gill tissue
can result in the imbalance of ion concentration and breathing
disorder, and the host eventually develops dyspnea and dies
from suffocation (Diggles and Adlard 1997;Lietal.2011;
Yosh in aga et a l. 2011).
Research results showed that C. irritans can infect most
marine teleosts (Burgess and Matthews 1995; Dan et al.
2008). However, in recent years, Siganus oramin was con-
firmed to possess a natural anti-C. irritans ability in the pub-
lished studies. It is because a L-amino acid oxidase exists in
the blood of S. oramin (Wang et al. 2011) which can induce
the cilium to fall off and plasmatorrhexis in C. irritans (Wang
et al. 2010). In addition, in the areas with a high prevalence of
cryptocaryoniasis in China, some culturists found that N.
albiflora did not die from cryptocaryoniasis even during dis-
ease outbreaks. Even if the mixed culture of Larimichthys
crocea, Lateolabrax japonicus, Pagrosomus major, and N.
albiflora was artificially infected with high-concentration C.
irritans (330 theronts per gram fish), L. crocea, L. japonicus,
and P. major were infected with varying degrees of death
within 96 h, while N. albiflora were all alive (Yin et al.
2018). So N. albiflora was used to hybridize with L. crocea
to obtain a high-quality breed (Sui et al. 2012). However, it
was intriguing whether C. irritans had infected N. albiflora at
all and what factors played the decisive role.
In our preliminary experiment, by continually increasing
the infection concentration, maximum sublethal concentration
Section Editor: Simonetta Mattiucci
* Fei Yin
* Baojun Tang
Key Laboratory of Applied Marine Biotechnology, Ministry of
Education; Collaborative Innovation Center for Zhejiang Marine
High-efficiency and Healthy Aquaculture, Ningbo University,
Ningbo 315211, People’sRepublicofChina
Key Laboratory of East China Sea and Oceanic Fishery Resources
Exploitation, Ministry of Agriculture, East China Sea Fisheries
Research Institute, Chinese Academy of Fishery Sciences,
Shanghai 200090, People’sRepublicofChina
College of Fisheries and Life Sciences, Shanghai Ocean University,
Shanghai 201306, People’sRepublicofChina
Parasitology Research (2018) 117:2379–2384