100
immunological memory (Fisher and Di Nuzzo 1991; Nyholm and McFall-Ngai
2004). Nonetheless, this system is quite effective to attach the pathogens they can
be exposed to and to manage the communities of resident bacteria present in the gut
(McFall-Ngai 2007). The cephalopod immune system works based on cellular factors. The haemocytes respond by phagocytosis, encapsulation, infiltration or cytotoxic activities to destroy or isolate pathogens (Beuerlein et al. 2002a). In addition,
haemocytes are also involved in the production of oxygen and nitrogen radicals
(Castellanos-Martínez et al. 2013; Ford 1992; Malham et al. 1997; Malham and
Runham 1998; Nyholm et al. 2009; Rodríguez-Domínguez et al. 2006). Destruction
of pathogens through phagocytosis or under haemocyte stimulation is complemented with the production of oxidative chemicals, frequently, the release of reactive
oxygen intermediates (ROIs), collectively known as respiratory burst (Chu 2000).
Another kind of oxidative chemical, which is part of the innate immune response, is
nitric oxide (NO). NO is a highly reactive free radical gas that is not stored and readily diffuses through membranes (Jacklet 1997), so it is an effective agent against
pathogens. Both oxidative chemicals have been identified in different cephalopod
species in response to stress and against pathogens (Castellanos-Martínez and Gestal 2013; Castellanos-Martínez et al. 2014; Malham et al. 2002; McFall-Ngai et al.
2010).
In addition, the dissolved molecules in the serum (opsonins, agglutinins, lysozyme) also contribute to the immune response of cephalopods (Ford 1992).These
humoral factors complement the cellular activity. Recently, Alpuche et al. (2010)
described a new lectin of 66 kDa (OmA) found in Octopus maya, and a homologue
to the type A haemocyanin from O� dofleini. Due to the specificity of this lectin
to galactosamine, mannose and fucose, these authors suggested that it could work
in the immune response by recognizing and agglutinating oligosaccharides from
pathogens. The enzyme lysozyme is also part of the defence mechanism. It has been
found in haemocytes and tissue from Eledone cirrhosa, showing higher activity in
haemocytes of octopuses infected by Vibrio anguillarum when measured immediately, compared to when measured after 4 and 24 h (Malham et al. 1998).
6.1.2.2 “Pathological Agents”
Virus
Viruses are the most abundant components of aquatic microbial communities
(Wommack and Colwell 2000). However, there are few records of viruses producing pathologies in cephalopods. Virus-like particles have been associated with tumours in O� vulgaris embedded in arm musculature and may be found in up to
8 % of wild specimens (Hanlon and Forsythe 1990a; Hanlon and Forsythe 1990b;
Rungger et al. 1971). In addition, virus-like particles have also been identified in the
stomach epithelium of S� officinalis, but without any detail related to what produced
the disease (Devauchelle and Vago 1971). Nonetheless, the latter authors suggested
that the development and structure of these particles appeared to be similar to those
of the vertebrate reovirus.
A. V. Sykes and C. Gestal
immunological memory (Fisher and Di Nuzzo 1991; Nyholm and McFall-Ngai
2004). Nonetheless, this system is quite effective to attach the pathogens they can
be exposed to and to manage the communities of resident bacteria present in the gut
(McFall-Ngai 2007). The cephalopod immune system works based on cellular factors. The haemocytes respond by phagocytosis, encapsulation, infiltration or cytotoxic activities to destroy or isolate pathogens (Beuerlein et al. 2002a). In addition,
haemocytes are also involved in the production of oxygen and nitrogen radicals
(Castellanos-Martínez et al. 2013; Ford 1992; Malham et al. 1997; Malham and
Runham 1998; Nyholm et al. 2009; Rodríguez-Domínguez et al. 2006). Destruction
of pathogens through phagocytosis or under haemocyte stimulation is complemented with the production of oxidative chemicals, frequently, the release of reactive
oxygen intermediates (ROIs), collectively known as respiratory burst (Chu 2000).
Another kind of oxidative chemical, which is part of the innate immune response, is
nitric oxide (NO). NO is a highly reactive free radical gas that is not stored and readily diffuses through membranes (Jacklet 1997), so it is an effective agent against
pathogens. Both oxidative chemicals have been identified in different cephalopod
species in response to stress and against pathogens (Castellanos-Martínez and Gestal 2013; Castellanos-Martínez et al. 2014; Malham et al. 2002; McFall-Ngai et al.
2010).
In addition, the dissolved molecules in the serum (opsonins, agglutinins, lysozyme) also contribute to the immune response of cephalopods (Ford 1992).These
humoral factors complement the cellular activity. Recently, Alpuche et al. (2010)
described a new lectin of 66 kDa (OmA) found in Octopus maya, and a homologue
to the type A haemocyanin from O� dofleini. Due to the specificity of this lectin
to galactosamine, mannose and fucose, these authors suggested that it could work
in the immune response by recognizing and agglutinating oligosaccharides from
pathogens. The enzyme lysozyme is also part of the defence mechanism. It has been
found in haemocytes and tissue from Eledone cirrhosa, showing higher activity in
haemocytes of octopuses infected by Vibrio anguillarum when measured immediately, compared to when measured after 4 and 24 h (Malham et al. 1998).
6.1.2.2 “Pathological Agents”
Virus
Viruses are the most abundant components of aquatic microbial communities
(Wommack and Colwell 2000). However, there are few records of viruses producing pathologies in cephalopods. Virus-like particles have been associated with tumours in O� vulgaris embedded in arm musculature and may be found in up to
8 % of wild specimens (Hanlon and Forsythe 1990a; Hanlon and Forsythe 1990b;
Rungger et al. 1971). In addition, virus-like particles have also been identified in the
stomach epithelium of S� officinalis, but without any detail related to what produced
the disease (Devauchelle and Vago 1971). Nonetheless, the latter authors suggested
that the development and structure of these particles appeared to be similar to those
of the vertebrate reovirus.
A. V. Sykes and C. Gestal