There are few studies investigating captive conditions for commonly kept public aquaria species. ... more There are few studies investigating captive conditions for commonly kept public aquaria species. Here the thornback ray (Raja clavata) was used to determine preferred captive conditions via choice tests and behavioural observations. Substrate type, substrate colour, substrate depth, group size and refuge use were all used to assess usage, number of stereotypic behaviours and activity in captive born rays. Sand was the preferred choice of substrate which also brought fewer surface breaking behaviours (a possible stereotypic behaviour) compared to gravel or bare tanks. Lighter colours of sand were preferred, as were deeper depths whilst increasing group size increased possible stereotypic behaviours. Type of resting behaviour (horizontal vs vertical) also differed within experiments − rays switched from horizontal to vertical resting, on the side of the tank when using gravelled versus sandy areas of the tank. The rays in this study appeared not to use refuges. Very few published studies have focused on what aquatic animals want, here we use preference tests, which are a useful way of determining what the animal wants, and can help aquarists provide the best conditions for captive thornback rays.
The European cuttlefish (Sepia officinalis) is often kept in public aquaria, is becoming more com... more The European cuttlefish (Sepia officinalis) is often kept in public aquaria, is becoming more common in aquaculture, and is also the most frequently used cephalopod in European research. Since 1st January 2013, all cephalopods (Mollusca) have been protected under UK/EU law (A(SP)A 1986, European Directive 2010/63/EU), following Australia, Canada and New Zealand. Presently, unlike other organisms used in research, there is no detailed specific guidance available from UK/EU legislators on best practices for keeping cuttlefish. In captivity, juveniles can easily become damaged by impacting with tank walls when startled. These injuries rarely heal and can have a major impact on growth and survival. Six experiments were performed, using juvenile and adult cuttlefish, in which exhibition of thigmotaxis in different environments, responses to simulated husbandry in different scenarios, and responses to typical and novel forms of enrichment (e.g. photographs of substrates) and refuges was investigated. Refuge use was also investigated, including response to husbandry when different refuges were provided. In addition to thigmotaxis, the frequency of negative behaviours (such as those likely indicating stress or preceding damaging behaviours) was recorded. The results suggest that certain environments, clothing/equipment and refuges/enrichment can significantly reduce the frequency of negative behaviours. It was also found fake seaweed and photographs of substrates placed in tanks may be used by cuttlefish with the benefit of preventing localised pollution. We conclude by providing an evidence-based guide to improving husbandry practices, which could improve the lives of captive cuttlefish.
The common European cuttlefish (Sepia officinalis) is frequently found in public aquaria in Europ... more The common European cuttlefish (Sepia officinalis) is frequently found in public aquaria in Europe. These remarkable creatures make fantastic display animals due to their rapid colour/texture/behaviour changes associated with feeding or camouflage. They possess extremely fragile bodies and soft tissues, adaptations thought to have evolved to evade predators, and in captivity cuttlefish can damage easily when startled or fleeing perceived threats and these injuries rarely heal, can cause permanent damage and even death. Knowing the signals which typically occur before damaging behaviours can reduce such incidents and therefore dramatically improve their welfare. Another aspect of captive animal welfare is providing suitable enrichment. Cuttlefish are adept at revealing how they feel about their present circumstances through deimatic displays, threat signals and defensive behaviours. Here, based on approximately two thousand hours of observations a very detailed welfare-focused behaviour table, a table summarising tank requirements/enrichment in cephalopods and an example care sheet derived from the observations are presented. This paper provides the resources to determine and prevent behaviours likely to precede damaging behaviours. Collating behaviours and sharing them with aquarists can be a valuable tool in preventing injuries and assessing wellbeing in captive animals.
The European cuttlefish (Sepia officinalis) is often kept in public aquaria, is becoming more com... more The European cuttlefish (Sepia officinalis) is often kept in public aquaria, is becoming more common in aquaculture, and is also the most frequently used cephalopod in European research. Since 1st January 2013, all cephalopods (Mollusca) have been protected under UK/EU law (A(SP)A 1986, European Directive 2010/63/EU), following Australia, Canada and New Zealand. Presently, unlike other organisms used in research, there is no detailed specific guidance available from UK/EU legislators on best practices for keeping cuttlefish. In captivity, juveniles can easily become damaged by impacting with tank walls when startled. These injuries rarely heal and can have a major impact on growth and survival. Six experiments were performed, using juvenile and adult cuttlefish, in which exhibition of thigmotaxis in different environments, responses to simulated husbandry in different scenarios, and responses to typical and novel forms of enrichment (e.g. photographs of substrates) and refuges was investigated. Refuge use was also investigated, including response to husbandry when different refuges were provided. In addition to thigmotaxis, the frequency of negative behaviours (such as those likely indicating stress or preceding damaging behaviours) was recorded. The results suggest that certain environments, clothing/equipment and refuges/enrichment can significantly reduce the frequency of negative behaviours. It was also found fake seaweed and photographs of substrates placed in tanks may be used by cuttlefish with the benefit of preventing localised pollution. We conclude by providing an evidence-based guide to improving husbandry practices, which could improve the lives of captive cuttlefish.
Much of the exceptional diversity of cichlid fishes in the African Great Lakes can be explained b... more Much of the exceptional diversity of cichlid fishes in the African Great Lakes can be explained by geographic variation among isolated populations of species specialised to live on patchily distributed rocky habitat. However, there are also many endemic species that are not specialised for rocky shores. These appear to experience weaker geographic isolation. Major decreases in lake volume may have segregated such populations in isolated refugia in the distant past, but subsequent range changes have likely eliminated most of the phylogeographic signal of these events. Divergence in currently isolated peripheral water bodies may be more amenable to the study of recent processes of allopatric divergence. We investigate a haplochromine cichlid fish, here referred to as Lethrinops sp. 'chilingali', isolated in a small satellite lake near Lake Malawi, and the candidate sister taxon, Lethrinops lethrinus, which inhabits shallow muddy habitats in the main lake and associated water bodies. The satellite lake form from Lake Chilingali showed significant morphological differentiation, with a less ventrally-placed mouth and shorter snout, associated with a shift in diet from a diverse range of benthic invertebrates towards specialisation on mid-water chaoborid larvae and pupae. The Lake Chilingali population showed substantially reduced mitochondrial DNA diversity and no haplotype sharing was observed with populations from the main lake system. In laboratory experiments, putative species showed a high degree of assortative mating and territorial males were significantly more aggressive towards intruders of their own population. This study adds to the evidence that rapid evolution of novel phenotypes in peripheral habitats can add to the diversity of lacustrine cichlids through the evolution of at least partial reproductive isolation in allopatry.
There are few studies investigating captive conditions for commonly kept public aquaria species. ... more There are few studies investigating captive conditions for commonly kept public aquaria species. Here the thornback ray (Raja clavata) was used to determine preferred captive conditions via choice tests and behavioural observations. Substrate type, substrate colour, substrate depth, group size and refuge use were all used to assess usage, number of stereotypic behaviours and activity in captive born rays. Sand was the preferred choice of substrate which also brought fewer surface breaking behaviours (a possible stereotypic behaviour) compared to gravel or bare tanks. Lighter colours of sand were preferred, as were deeper depths whilst increasing group size increased possible stereotypic behaviours. Type of resting behaviour (horizontal vs vertical) also differed within experiments − rays switched from horizontal to vertical resting, on the side of the tank when using gravelled versus sandy areas of the tank. The rays in this study appeared not to use refuges. Very few published studies have focused on what aquatic animals want, here we use preference tests, which are a useful way of determining what the animal wants, and can help aquarists provide the best conditions for captive thornback rays.
The European cuttlefish (Sepia officinalis) is often kept in public aquaria, is becoming more com... more The European cuttlefish (Sepia officinalis) is often kept in public aquaria, is becoming more common in aquaculture, and is also the most frequently used cephalopod in European research. Since 1st January 2013, all cephalopods (Mollusca) have been protected under UK/EU law (A(SP)A 1986, European Directive 2010/63/EU), following Australia, Canada and New Zealand. Presently, unlike other organisms used in research, there is no detailed specific guidance available from UK/EU legislators on best practices for keeping cuttlefish. In captivity, juveniles can easily become damaged by impacting with tank walls when startled. These injuries rarely heal and can have a major impact on growth and survival. Six experiments were performed, using juvenile and adult cuttlefish, in which exhibition of thigmotaxis in different environments, responses to simulated husbandry in different scenarios, and responses to typical and novel forms of enrichment (e.g. photographs of substrates) and refuges was investigated. Refuge use was also investigated, including response to husbandry when different refuges were provided. In addition to thigmotaxis, the frequency of negative behaviours (such as those likely indicating stress or preceding damaging behaviours) was recorded. The results suggest that certain environments, clothing/equipment and refuges/enrichment can significantly reduce the frequency of negative behaviours. It was also found fake seaweed and photographs of substrates placed in tanks may be used by cuttlefish with the benefit of preventing localised pollution. We conclude by providing an evidence-based guide to improving husbandry practices, which could improve the lives of captive cuttlefish.
The common European cuttlefish (Sepia officinalis) is frequently found in public aquaria in Europ... more The common European cuttlefish (Sepia officinalis) is frequently found in public aquaria in Europe. These remarkable creatures make fantastic display animals due to their rapid colour/texture/behaviour changes associated with feeding or camouflage. They possess extremely fragile bodies and soft tissues, adaptations thought to have evolved to evade predators, and in captivity cuttlefish can damage easily when startled or fleeing perceived threats and these injuries rarely heal, can cause permanent damage and even death. Knowing the signals which typically occur before damaging behaviours can reduce such incidents and therefore dramatically improve their welfare. Another aspect of captive animal welfare is providing suitable enrichment. Cuttlefish are adept at revealing how they feel about their present circumstances through deimatic displays, threat signals and defensive behaviours. Here, based on approximately two thousand hours of observations a very detailed welfare-focused behaviour table, a table summarising tank requirements/enrichment in cephalopods and an example care sheet derived from the observations are presented. This paper provides the resources to determine and prevent behaviours likely to precede damaging behaviours. Collating behaviours and sharing them with aquarists can be a valuable tool in preventing injuries and assessing wellbeing in captive animals.
The European cuttlefish (Sepia officinalis) is often kept in public aquaria, is becoming more com... more The European cuttlefish (Sepia officinalis) is often kept in public aquaria, is becoming more common in aquaculture, and is also the most frequently used cephalopod in European research. Since 1st January 2013, all cephalopods (Mollusca) have been protected under UK/EU law (A(SP)A 1986, European Directive 2010/63/EU), following Australia, Canada and New Zealand. Presently, unlike other organisms used in research, there is no detailed specific guidance available from UK/EU legislators on best practices for keeping cuttlefish. In captivity, juveniles can easily become damaged by impacting with tank walls when startled. These injuries rarely heal and can have a major impact on growth and survival. Six experiments were performed, using juvenile and adult cuttlefish, in which exhibition of thigmotaxis in different environments, responses to simulated husbandry in different scenarios, and responses to typical and novel forms of enrichment (e.g. photographs of substrates) and refuges was investigated. Refuge use was also investigated, including response to husbandry when different refuges were provided. In addition to thigmotaxis, the frequency of negative behaviours (such as those likely indicating stress or preceding damaging behaviours) was recorded. The results suggest that certain environments, clothing/equipment and refuges/enrichment can significantly reduce the frequency of negative behaviours. It was also found fake seaweed and photographs of substrates placed in tanks may be used by cuttlefish with the benefit of preventing localised pollution. We conclude by providing an evidence-based guide to improving husbandry practices, which could improve the lives of captive cuttlefish.
Much of the exceptional diversity of cichlid fishes in the African Great Lakes can be explained b... more Much of the exceptional diversity of cichlid fishes in the African Great Lakes can be explained by geographic variation among isolated populations of species specialised to live on patchily distributed rocky habitat. However, there are also many endemic species that are not specialised for rocky shores. These appear to experience weaker geographic isolation. Major decreases in lake volume may have segregated such populations in isolated refugia in the distant past, but subsequent range changes have likely eliminated most of the phylogeographic signal of these events. Divergence in currently isolated peripheral water bodies may be more amenable to the study of recent processes of allopatric divergence. We investigate a haplochromine cichlid fish, here referred to as Lethrinops sp. 'chilingali', isolated in a small satellite lake near Lake Malawi, and the candidate sister taxon, Lethrinops lethrinus, which inhabits shallow muddy habitats in the main lake and associated water bodies. The satellite lake form from Lake Chilingali showed significant morphological differentiation, with a less ventrally-placed mouth and shorter snout, associated with a shift in diet from a diverse range of benthic invertebrates towards specialisation on mid-water chaoborid larvae and pupae. The Lake Chilingali population showed substantially reduced mitochondrial DNA diversity and no haplotype sharing was observed with populations from the main lake system. In laboratory experiments, putative species showed a high degree of assortative mating and territorial males were significantly more aggressive towards intruders of their own population. This study adds to the evidence that rapid evolution of novel phenotypes in peripheral habitats can add to the diversity of lacustrine cichlids through the evolution of at least partial reproductive isolation in allopatry.
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Papers by Gavan Cooke
These remarkable creatures make fantastic display animals due to their rapid colour/texture/behaviour
changes associated with feeding or camouflage. They possess extremely fragile bodies and soft tissues,
adaptations thought to have evolved to evade predators, and in captivity cuttlefish can damage easily
when startled or fleeing perceived threats and these injuries rarely heal, can cause permanent damage
and even death. Knowing the signals which typically occur before damaging behaviours can reduce
such incidents and therefore dramatically improve their welfare. Another aspect of captive animal
welfare is providing suitable enrichment. Cuttlefish are adept at revealing how they feel about their
present circumstances through deimatic displays, threat signals and defensive behaviours. Here, based
on approximately two thousand hours of observations a very detailed welfare-focused behaviour
table, a table summarising tank requirements/enrichment in cephalopods and an example care sheet
derived from the observations are presented. This paper provides the resources to determine and
prevent behaviours likely to precede damaging behaviours. Collating behaviours and sharing them with
aquarists can be a valuable tool in preventing injuries and assessing wellbeing in captive animals.
These remarkable creatures make fantastic display animals due to their rapid colour/texture/behaviour
changes associated with feeding or camouflage. They possess extremely fragile bodies and soft tissues,
adaptations thought to have evolved to evade predators, and in captivity cuttlefish can damage easily
when startled or fleeing perceived threats and these injuries rarely heal, can cause permanent damage
and even death. Knowing the signals which typically occur before damaging behaviours can reduce
such incidents and therefore dramatically improve their welfare. Another aspect of captive animal
welfare is providing suitable enrichment. Cuttlefish are adept at revealing how they feel about their
present circumstances through deimatic displays, threat signals and defensive behaviours. Here, based
on approximately two thousand hours of observations a very detailed welfare-focused behaviour
table, a table summarising tank requirements/enrichment in cephalopods and an example care sheet
derived from the observations are presented. This paper provides the resources to determine and
prevent behaviours likely to precede damaging behaviours. Collating behaviours and sharing them with
aquarists can be a valuable tool in preventing injuries and assessing wellbeing in captive animals.