Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

We conducted an investigation into ghost fishing, a phenomenon in which abandoned fishing equipment remains operational for extended durations, in the southern region of Lake Tanganyika, Republic of Zambia. The perils associated with ghost fishing have achieved international recognition; however, there exists a conspicuous dearth of scholarly investigations in particular regions, notably inland aquatic environments and developing countries. Employing scuba diving for field observations, we discovered that ghost fishing was solely evident in monofilament nylon nets, despite the presence of four different net types in the littoral area of the lake. Notably, endemic crabs Platythelphusa armata and P. maculata from Lake Tanganyika constituted 65.2% of the organisms captured by abandoned nets, with the remainder comprising various fish species. The number of captured organisms exhibited a dependence on the interplay between the length and mesh size of the abandoned nets, indicating that the risk of ghost fishing is heightened when both net and mesh size are substantial. Furthermore, we encountered predatory Spiny Eels Mastacembelus moorii ensnared in nets around their jaws and teeth. Intriguingly, the digestive tract of one of the Spiny Eels contained a partially digested cichlid species entangled in the same nets, strongly suggesting the occurrence of secondary ghost fishing.

DOI： 10.1002/fsh.11061

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Publishing type：Research paper (scientific journal)   Publisher：Zoological Society of Japan  

DOI： 10.2108/zs220088

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Proceedings of the National Academy of Sciences  

<jats:p>
Some animals have the remarkable capacity for mirror self-recognition (MSR), yet any implications for self-awareness remain uncertain and controversial. This is largely because explicit tests of the two potential mechanisms underlying MSR are still lacking: mental image of the self and kinesthetic visual matching. Here, we test the hypothesis that MSR ability in cleaner fish,
<jats:italic>Labroides dimidiatus</jats:italic>
, is associated with a mental image of the self, in particular the self-face, like in humans
<jats:italic>.</jats:italic>
Mirror-naive fish initially attacked photograph models of both themselves and unfamiliar strangers. In contrast, after all fish had passed the mirror mark test, fish did not attack their own (motionless) images, but still frequently attacked those of unfamiliar individuals. When fish were exposed to composite photographs, the self-face/unfamiliar body were not attacked, but photographs of unfamiliar face/self-body were attacked, demonstrating that cleaner fish with MSR capacity recognize their own facial characteristics in photographs. Additionally, when presented with self-photographs with a mark placed on the throat, unmarked mirror-experienced cleaner fish demonstrated throat-scraping behaviors. When combined, our results provide clear evidence that cleaner fish recognize themselves in photographs and that the likely mechanism for MSR is associated with a mental image of the self-face, not a kinesthetic visual-matching model. Humans are also capable of having a mental image of the self-face, which is considered an example of private self-awareness. We demonstrate that combining mirror test experiments with photographs has enormous potential to further our understanding of the evolution of cognitive processes and private self-awareness across nonhuman animals.
</jats:p>

DOI： 10.1073/pnas.2208420120

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

"Face" is a special stimulus in humans and, nonhuman primates, and some other social mammals; that is, they perceive the face differently from the other body parts and other stimuli. In these species, the face conveys much information, so individuals examine the face at first sight rather than other body parts. Similar to mammals, the faces offish also convey much information, but little is known about whether fish pay attention to the face or face-viewing patterns. Here we document the face-viewing patterns of the cichlid fish Neolamprologus brichardi, which can distinguish between conspecifics based on facial colouration. First, we established a method to identify the point at which subject fish inspected. Fish often fixated in direction to their heads toward the object of attention, suggesting that the extended body axis indicated the attention point. Using this attribute, we examined the point of attention of subject fish presented with photographs of conspecifics and heterospecifics. The results revealed that the fish inspected initially and repeatedly at the face and the duration was longer for the face than other body parts.

DOI： 10.1038/s41598-019-44715-0

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER HEIDELBERG  

Faces are the most important body part for differentiating among human individuals by humans. Humans read the face as a whole, rather than looking at its parts, which makes it more difficult to recognise inverted faces than upright. Some other mammals also identify each other based on the upright face and take longer to recognise inverted faces. This effect is called the face inversion effect and is considered as evidence for face-specific perception. This ability has rarely been observed in animals other than mammals, but it was recently reported that some fish species could distinguish among individuals based on the face. For example, the cichlid fish Neolamprologus pulcher rapidly recognises familiar conspecifics by faces rather than other body parts. Here, we examined the face inversion effect in N. pulcher, by showing photographs of conspecific fish faces and objects in both upright and inverted orientations. Subjects gazed at novel faces longer than familiar faces in upright presentation, whereas they did not show such a tendency for inverted faces. Although the object discrimination was difficult, we did not observe the difference between upright and inverted object photographs. Our results indicate that fish exhibits the inversion effect for faces. These findings suggest that N. pulcher may process their conspecifics' face holistically, like humans.

DOI： 10.1007/s10071-018-01231-4

Web of Science

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Authorship：Lead author   Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：The Ichthyological Society of Japan  

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Event date： 2023.3

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

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Event date： 2022.7 - 2022.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Stockholm   Country：Sweden  

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Event date： 2021.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Online  

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Event date： 2017.7 - 2017.8

Language：English   Presentation type：Poster presentation  

Venue：Lisbon   Country：Portugal  

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Event date： 2024.3

Language：Japanese   Presentation type：Poster presentation  

Country：Japan  

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Author：Other 

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