Journal of Threatened
Taxa | www.threatenedtaxa.org | 26 November 2025 | 17(11): 28001–28003
ISSN 0974-7907 (Online)
| ISSN 0974-7893 (Print)
https://doi.org/10.11609/jott.10001.17.11.28001-28003
#10001 | Received 16
June 2025 | Finally accepted 27 October 2025
Crab eating crab: first record of
the Horn-eyed Ghost Crab Ocypode brevicornis preying on the Mottled Light-footed Crab Grapsus albolineatus
in Visakhapatnam, India
Harish Prakash 1, M.K. Abhisree 2 & Rohan Kumar 3
1,2,3 Department of Life Sciences,
GITAM School of Science, GITAM (Deemed to be University), Visakhapatnam, Andhra
Pradesh, India.
1 harishprakashhp@gmail.com
(corresponding author), 2 abhisreemk@gmail.com, 3 rk070088@gmail.com
Editor: Hari Praved, Cochin University of Science and Technology,
Kerala, India. Date of publication: 26 November 2025 (online & print)
Citation: Prakash,
H., M.K. Abhisree & R. Kumar (2025). Crab eating
crab: first record of the Horn-eyed Ghost Crab Ocypode
brevicornis preying on the Mottled Light-footed
Crab Grapsus albolineatus
in Visakhapatnam, India. Journal of
Threatened Taxa 17(11):
28001–28003. https://doi.org/10.11609/jott.10001.17.11.28001-28003
Copyright: © Prakash et al. 2025. Creative Commons Attribution 4.0 International License.
JoTT allows unrestricted use, reproduction, and
distribution of this article in any medium by providing adequate credit to the
author(s) and the source of publication.
Funding: GITAM : Research Seed Grants (RSG); Ref: F.No 2024/0320.
Competing interests: The authors declare no competing interests.
Acknowledgements: We would like to thank the Gandhi Institute of Technology and Management (GITAM), Deemed to be Univeristy, for the Research Seed Grant (2024/0320) that enabled us to kickstart exploring the intertidal zones. Also, I would like to thank UGC for the Abhisree M. K.’s JRF fellowship.
One of the
classic studies by Paine (1966) demonstrated how the keystone predator, the
Ochre Sea Star Pisaster ochraceus,
regulates species composition and maintains diversity in rocky intertidal
communities. Similarly, in sandy intertidal zones, ghost crabs (genus Ocypode, family Ocypodidae)
act as important keystone predators by influencing benthic invertebrate
populations and sediment dynamics, thereby shaping the ecological structure of
these habitats. These sand burrowing crabs are called ‘ghosts’ for their pale
sand blending colour, their swift movement to escape
threat, and their predominant nocturnal activity (Lucrezi
& Schlacher 2014). All ghost crabs are
morphologically characterised by their box-shaped
carapace, long eye stalk, and unequally sized claws. They are distributed all
across the tropics and temperate zones, from the coast of the Atlantic Ocean
and the Mediterranean Sea to the eastern Pacific Ocean and the Indo-west
Pacific Ocean (Sakai & Türkay 2013). Along the Indian
coast, there are at least six recorded species of ghost crabs – O. brevicornis, O. ceratophthalmus,
O. cordimana, O. macrocera,
O. pallidula, and O. rotundata
(Sakai & Türkay 2013; Lucrezi
& Schlacher 2014). Of the six, we have
observed at least three species in Rushikonda Beach,
Visakhapatnam – O. brevicornis (Image 1),
O. macrocera, and O. cordimanus.
Ghost crabs
play a key role in the intertidal ecosystem. The burrowing activity of crabs on
the sandy shores causes bioturbation, mixing sediments and thereby influencing
nutrient cycling and overall ecosystem functioning (Dubey et al. 2013; An et
al. 2021). Moreover, ghost crabs serve as a key link in intertidal food webs,
functioning as apex invertebrate consumers and scavengers while also serving as
prey for vertebrates. Their diet ranges from the microscopic organic materials,
to macroscopic dendrites of seaweeds and seagrass, animal carcasses beached on
the shore, and live invertebrate & vertebrate prey that the crabs can catch
and handle (Lucrezi & Schlacher
2014; Vale et al. 2022). Initially, assumed to be predominantly scavengers,
there is increasing evidence that ghost crabs are significant apex predators
that hunt and feed in the intertidal zone (Wolcott 1978; Kwon et al. 2018; Yong
& Lim 2019). They are known to actively prey on clams, gastropods, annelid
worms, isopods, shrimps, various kinds of insects, and eggs & young ones of
nesting birds and turtles (Lucrezi & Schlacher 2014). They are also known to prey on other crabs
such as hermit crabs (family Paguroidea), mole crabs
(Hippidae), fiddler crabs (Ocypodidae),
box crabs (Calappidae), portunid
crabs (Portunidae), sentinel crabs (Macrophthalmidae), and ghost crabs (Branco et al. 2010; Chartosia et al. 2010).
To the best
of our knowledge, this is the first documented observation of the O. brevicornis actively handling a G. albolineatus (family: Grapsidae)
(Image 3 & 4). This observation made at Rushikonda
Beach, Visakhapatnam, on April 2025 is unique since the O. brevicornis is usually found only on the sandy section
of the beach, while the G. albolineatus is
found in the rocky section (Image 2). This natural history observation
highlights the sand-dwelling ghost crabs’ possible foray into the rocky
sections of the intertidal zone as a part of their nocturnal foraging activity.
Such predator-prey interaction might be restricted to areas of the beach where
rocky and sandy habitats co-occur within the intertidal zone.
Ghost crabs
are generalists and opportunistic feeders, with their diet depends on local
prey availability and seasonal variation (Vale et al. 2022). Given the wide
geographical distribution of O. brevicornis along
the Indian coast, dietary patterns likely vary spatially. Such differences in
marine predator-prey interactions might also arise from the impact of
disturbance to the intertidal ecosystem in the form of pollution (Johnston
& Roberts 2009) and climate change (Harley 2011). Studies in the future,
should systematically examine the diet of apex invertebrate predators like
ghost crabs. Such studies will improve our understanding of predator-prey
interactions and their spatio-temporal variation
along the coast. It also helps infer the impact of such interactions on
intertidal community dynamics and broader marine ecosystem functioning.
Ethical
statement: This observation was based solely on animals in their natural habitat.
No manipulation or disturbance was caused to them during the observation except
for the brief headlamp light and flash from the camera. Therefore, no ethical
approval was required.
For
images - - click here for full PDF
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