Dietary Bacillus improves behavior, intestinal health, and growth of juvenile sea cucumbers Apostichopus japonicus at low temperature.

The traditional overwintering process of sea cucumbers (Apostichopus japonicus) requires burning a large amount of coal to raise the water temperature. It is useful but costly and not environmentally friendly. Bacillus is proposed as a cheap and green alternative.

Dietary tryptophan decreases the impacts of seawater temperature changes on behavior and gut health of the sea cucumber Apostichopus japonicus.

Seawater temperature change is an important concern for seed production and pond culture of sea cucumbers. The present study found that tentacle activity frequency was significantly lower in sea cucumbers exposed to continuous and rapid temperature increases than that of those at ambient temperature. Feeding behavior directly determines food intake, and further affects physiology and growth efficiency of sea cucumbers.

Behavior, intestinal health, and growth of small sea cucumbers Apostichopus japonicus in different color morphs.

Selecting high-quality seeds with long-term advantages in behavior, intestinal health, and growth are the key to improve production efficiency of sea cucumber aquaculture. It is proposed to distinguish the seed quality of sea cucumbers by color morphs. In the present study, we carried out a 6-week experiment to investigate behavior, intestinal health, and growth of small sea cucumbers Apostichopus japonicus in different color morphs.

Swing Regulates Movement Direction in the Sea Cucumber in the Presence of Food Cue: New Insights into Movement Patterns.

Regulating movement direction is essential in the locomotion of animals. Sea cucumbers, as eyeless animals, do not have eyes for the perception of the surrounding environment and food. They have a unique way of swinging their bodies when a food cue is detected, although they lack an important perceptual tool.

Bacillus licheniformis reduces mortality, improves symptoms, and controls residual pathogenicity in juvenile sea cucumbers Apostichopus japonicus infected with skin ulceration syndrome.

Mass mortality caused by skin ulceration syndrome (SUS) is the bottle-neck for the sustainable aquaculture of the sea cucumber Apostichopus japonicus. In the present study, probiotic Bacillus licheniformis (0.25 × 10 CFU/g) was used as the treatment for A.

Effects of circadian rhythm on behavior and physiology of the sea cucumber Apostichopus japonicus.

The present study investigated the behavioral and physiological responses to the circadian rhythm in the sea cucumber Apostichopus japonicus. We found that righting behavior of sea cucumbers was significantly faster at night than that in daytime (P < 0.001).

The feces of sea urchins as food improves survival, growth, and resistance of small sea cucumbers Apostichopus japonicus in summer.

Mass mortality and low growth highly decrease the production efficiency and sustainable aquaculture development of the sea cucumber Apostichopus japonicus in summer. Sea urchin feces was proposed to address the summer problems. A laboratory study was conducted for ~ 5 weeks to investigate survival, food consumption, growth and resistance ability of A.

Ecological niche models for the assessment of site suitability of sea cucumbers and sea urchins in China.

In the present study, the maximum entropy model (MaxEnt) based on the data of sea surface temperature (SST) and published information was used to assess the site suitability for the aquaculture expansion of the sea cucumber Apostichopus japonicus and the sea urchin Strongylocentrotus intermedius in China. According to the current assessment, the coastal areas of Hebei province and Tianjin have great prospects for A. japonicus aquaculture, while is currently being underutilized.

Macroalgae and interspecific alarm cues regulate behavioral interactions between sea urchins and sea cucumbers.

Sea urchins and sea cucumbers are mutually beneficial organisms in kelp ecosystem. As herbivores, sea urchins process kelp through feeding and egestion, providing inaccessible food for benthic consumers such as sea cucumbers. Sea urchins in turn profit from the sediment cleaned by sea cucumbers.

High fitness areas drive the aggregation of the sea urchin .

Sea urchin aggregation is a common phenomenon in coastlines. However, it remains controversial whether sea urchins form resource aggregations or behavioral aggregations in a non-spawning season. To clarify, we studied the aggregative responses to food and predators in the sea urchin when high fitness areas (HFAs) were scarce versus sufficient.

Foraging behavior of the sea urchin Mesocentrotus nudus exposed to conspecific alarm cues in various conditions.

Conspecific alarm cues crushed from Mesocentrotus nudus prevent sea urchins from foraging the kelp, but do not repel them far away from the kelp. However, it remains largely unknown of whether this phenomenon was affected by conspecific alarm cues or by the attraction of the kelp. The present study found no significant difference in the duration in the danger area with or without the kelp around conspecific alarm cues.

Interaction among sea urchins in response to food cues.

Interaction among sea urchins remains largely uninvestigated, although the aggregation of sea urchins is common. In the present study, 1, 15 and 30 sea urchins Strongylocentrotus intermedius (11.06 ± 0.

Fitness benefits and costs of shelters to the sea urchin .

Understanding the ecological role of shelters is greatly hampered by the scarcity of long-term laboratory experiments on the trade-off between fitness benefits and costs. This lack probably leads to an underestimation of the negative and/or positive effects on behaviors and growth of marine invertebrates in benthic ecosystems. Although our previous study revealed a significant effect on fitness-related traits of after 31 months, the present study extended it and investigated fitness benefits and/or costs of long-term sheltering on sea urchins to over 7 years.

Light intensity regulates phototaxis, foraging and righting behaviors of the sea urchin .

Small sea urchins (1-2 cm of test diameter) are exposed to different environments of light intensities after being reseeded to the sea bottom. With little information available about the behavioral responses of to different light intensities in the environment, we carried out an investigation on how is affected by three light intensity environments in terms of phototaxis, foraging and righting behaviors. They were no light (zero lx), low light intensity (24-209 lx) and high light intensity (252-2,280 lx).