101
Other reports include the identification of virus-like particles in the epithelial
cells of the tubules of the digestive gland of Loligo pealei and in the renal appendages of several octopod species (Hanlon and Forsythe 1990b).
Bacteria
Bacterial infections are usually developed on the cephalopod’s mantle after injuries
produced during collection or on lesions suffered in captivity (Hanlon et al. 1988),
which cause the spread of the infection to other organisms sharing the tank (Hanlon
et al. 1983). A number of bacterial infections of cultured cephalopods were summarized by Hanlon and Forsythe (1990a) in their review of cephalopod diseases. Vibriosis is the most significant bacterial disease encountered in cephalopods (Sherrill
et al. 2000).
Hanlon et al. (1984) observed “skin ulcers” on the dorsal mantle, head and arms
showing hyperplasia of the epidermis and increased mucus production in high-density rearing of O� joubini and O� briareus. Gram-negative bacteria including V� alginolyticus, V� damsela, Pseudomonas stutzeri and Aeromonas caviae were isolated
from O� joubini ulcers, while V� parahaemolyticus, V� damsela and P� stutzeri where
isolated from ulcers of O� briareus which resulted in chromatophore damage.
Ford et al. (1986) described the bacterial populations of normal and ulcerated
mantle in Lolliguncula brevis and found that laboratory-maintained squids had significantly higher viable bacterial cells per cm
2
of mantle tissue than wild squids,
although the latter had a slightly higher species diversity. Thus, the gram-negative
bacteria Aeromonas sp., Flavobacterium sp., Pseudomonas sp., Vibrio sp., Proteus
sp., V� parahaemolyticus, V� alginolyticus and Flexibacter as well as the gram-positive bacteria Bacillus sp., Streptococcus sp., Staphylociccus sp., Micrococcus sp.
and Planococcus sp. were identified in wild squids. In laboratory-maintained squids,
V� alginiolyticus, Vibrio sp., Aeromonas sp., V� paraahaemolyticus, V� metschnikovii,
Flavobacterium sp., Proteus sp., Bacillus sp. and Streptococcus sp. were identified
in normal-skin squids, and V� alginolyticus, Vibrio sp., V� metschinikovii, Aeromonas
sp., Pseudomonas sp., Bacillus sp. and Staphylococcus sp. were identified in squids
showing ulcerated skin.
Mantle and arms are not the only tissues susceptible to bacterial infection. The
gills of reared O� vulgaris have been found to be infected by Rickettsiales-like organisms observed in the form of basophilic intracytoplasmic microcolonies within
epithelial cells. The invaded cells were hypertrophic and necrosis was occasionally
observed. No significant harm has been observed in the host, but under culture conditions, bacteria are able to have a detrimental effect on the host respiratory gaseous
exchange (Gestal et al. 1998).
Farto et al. (2003) identified the gram-negative bacteria V� lentus isolated for
the first time from an octopus’s internal organ, in the gill heart of wild O� vulgaris.
The specimens also showed lesions in the mantle tissue. Experimental infections in
the laboratory demonstrated that V� lentus induced mortality in 50 % of octopuses
in the first 6 h. The lesions showed a typical round pattern in the arms or head. According to these authors, low salinity (29 %) could be a stressing factor related to
6 Welfare and Diseases Under Culture Conditions
Other reports include the identification of virus-like particles in the epithelial
cells of the tubules of the digestive gland of Loligo pealei and in the renal appendages of several octopod species (Hanlon and Forsythe 1990b).
Bacteria
Bacterial infections are usually developed on the cephalopod’s mantle after injuries
produced during collection or on lesions suffered in captivity (Hanlon et al. 1988),
which cause the spread of the infection to other organisms sharing the tank (Hanlon
et al. 1983). A number of bacterial infections of cultured cephalopods were summarized by Hanlon and Forsythe (1990a) in their review of cephalopod diseases. Vibriosis is the most significant bacterial disease encountered in cephalopods (Sherrill
et al. 2000).
Hanlon et al. (1984) observed “skin ulcers” on the dorsal mantle, head and arms
showing hyperplasia of the epidermis and increased mucus production in high-density rearing of O� joubini and O� briareus. Gram-negative bacteria including V� alginolyticus, V� damsela, Pseudomonas stutzeri and Aeromonas caviae were isolated
from O� joubini ulcers, while V� parahaemolyticus, V� damsela and P� stutzeri where
isolated from ulcers of O� briareus which resulted in chromatophore damage.
Ford et al. (1986) described the bacterial populations of normal and ulcerated
mantle in Lolliguncula brevis and found that laboratory-maintained squids had significantly higher viable bacterial cells per cm
2
of mantle tissue than wild squids,
although the latter had a slightly higher species diversity. Thus, the gram-negative
bacteria Aeromonas sp., Flavobacterium sp., Pseudomonas sp., Vibrio sp., Proteus
sp., V� parahaemolyticus, V� alginolyticus and Flexibacter as well as the gram-positive bacteria Bacillus sp., Streptococcus sp., Staphylociccus sp., Micrococcus sp.
and Planococcus sp. were identified in wild squids. In laboratory-maintained squids,
V� alginiolyticus, Vibrio sp., Aeromonas sp., V� paraahaemolyticus, V� metschnikovii,
Flavobacterium sp., Proteus sp., Bacillus sp. and Streptococcus sp. were identified
in normal-skin squids, and V� alginolyticus, Vibrio sp., V� metschinikovii, Aeromonas
sp., Pseudomonas sp., Bacillus sp. and Staphylococcus sp. were identified in squids
showing ulcerated skin.
Mantle and arms are not the only tissues susceptible to bacterial infection. The
gills of reared O� vulgaris have been found to be infected by Rickettsiales-like organisms observed in the form of basophilic intracytoplasmic microcolonies within
epithelial cells. The invaded cells were hypertrophic and necrosis was occasionally
observed. No significant harm has been observed in the host, but under culture conditions, bacteria are able to have a detrimental effect on the host respiratory gaseous
exchange (Gestal et al. 1998).
Farto et al. (2003) identified the gram-negative bacteria V� lentus isolated for
the first time from an octopus’s internal organ, in the gill heart of wild O� vulgaris.
The specimens also showed lesions in the mantle tissue. Experimental infections in
the laboratory demonstrated that V� lentus induced mortality in 50 % of octopuses
in the first 6 h. The lesions showed a typical round pattern in the arms or head. According to these authors, low salinity (29 %) could be a stressing factor related to
6 Welfare and Diseases Under Culture Conditions