MARINE AND FISHERY SCIENCES 36 (2): 197-202 (2023)
ABSTRACT. Porpita porpita occurs in the tropical and sub-tropical waters of the Pacific,
Atlantic, and Indian Oceans, and the mass numbers of stranded colonies seem to be increasing.
Although its presence in Indian waters is minimal, this is the first record ever made of P. porpita in
Visakhapatnam coastal waters. The present study provided a detailed description of the species and
its global distribution. Further, the perceived increase in gelatinous zooplankton blooms in the
observed area indicates that jellyfish can negatively affect fisheries because they compete with zoo-
planktivorous fish, prey upon fish eggs and larvae, and indirectly compete with higher trophic levels
by reducing the plankton available to planktivores. Conversely, jellyfishes also play a vital role in
regulating global marine plankton food webs, spatio-temporal dynamics, and biomass, which is a
role that has been generally neglected so far.
Key words: Jellyfish, Porpitidae, fisheries, gelatinous zooplankton, food web.
Arribazón de medusa azul Porpita porpita en las playas de Visakhapatnam, India (Bahía occi-
dental de Bengala)
RESUMEN. Porpita porpita se encuentra en las aguas tropicales y subtropicales de los océanos
Pacífico, Atlántico e Índico, y el número masivo de colonias varadas parece estar aumentando. Aun-
que su presencia en las aguas de la India es mínima, este es el primer registro de P. porpita en las
aguas costeras de Visakhapatnam. El presente estudio proporcionó una descripción detallada de la
especie y su distribución global. Además, el aumento percibido en las floraciones de zooplancton
gelatinoso en el área observada, indica que las medusas pueden afectar negativamente a las pesque-
rías porque compiten con los peces zooplanctívoros, se alimentan de huevos y larvas de peces, e
indirectamente compiten con niveles tróficos más altos al reducir el plancton disponible para los
planctívoros. Por el contrario, las medusas también juegan un papel vital en la regulación de las
redes alimentarias del plancton marino global, la dinámica espacio-temporal y la biomasa, un papel
que generalmente se ha descuidado hasta ahora.
Palabras clave: Medusa, Porpitidae, pesquerías, zooplancton gelatinoso, trama trófica.
Porpita porpita (Linnaeus, 1758), commonly known as ‘blue button jelly’,
is a colony of Hydrozoa belonging to the Order Anthoathecata, Family Por-
pitidae, which includes three genera: Porpema Haeckel, 1888; Velella Lamar-
ck, 1801 and Porpita Lamarck, 1801. It is an open ocean species found glob-
ally in tropical and sub-tropical waters of the Pacific, Atlantic, and Indian
oceans (Zhang 1999; Kirkendale and Calder 2003; Bouillon et al. 2004;
Received: 22 January 2023
Accepted: 7 March 2023
ISSN 2683-7595 (print)
ISSN 2683-7951 (online)
Journal of the Instituto Nacional de
Investigación y Desarrollo Pesquero
This work is licensed under a Creative
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International License
Marine and
Fishery Sciences
Stranding of blue button jelly Porpita porpita (Cnidaria: Hydrozoa) on the
beaches of Visakhapatnam, India (Western Bay of Bengal)
1Fishery Survey of India, Kochi, India. 2Fishery Survey of India, Chennai, India. 3Fishery Survey of India, Visakhapatnam, India.
ORCID Krishnan Silambarasan, Annada Bhusan Kar
Kubota and Tanase 2007; Fisner et al. 2008;
Gravili et al. 2008; Calder 2010; Pandya et al.
2013; Gul and Gravili 2014). The species was
first described by Linnaeus (1758) as Medusa
porpita. Numerous nominal species of Porpita
Lamarck, 1801, have been described over the
years, but all are now synonymised for a single
species, P. porpita (Calder 1988; Schuchert
2013). It is inhabiting the ocean surface although
habitats of larvae and medusae may extend up to
200 m depth. This species is the dweller of the
uppermost layer of the marine environment and is
easily carried to shore by water currents and wind
(Pandya et al. 2013).
The species P. porpita actively feeds on
diverse zooplanktonic prey, including copepods,
cladocerans, larval forms of small crustaceans
and molluscs (Ganapati and Subba Rao 1959). In
addition, P. porpita colonies and medusae host
symbiotic zooxanthellae that may provide nutri-
tion. It is predated by a diverse vertebrate preda-
tor and specially gastropods, mostly Glaucus spp.
and Janthina spp. (Chowdhury et al. 2016; Lep-
oint et al. 2016; Phillips et al. 2017).
Porpita porpita is notable for forming huge
rafts at sea and for massive beach strandings and
aggregations that have been reported in various
parts of the world’s oceans (Chowdhury et al.
2016; Madkour et al. 2019; Mamish et al. 2019;
Gurlek et al. 2020; Sahu et al. 2020; Boukhicha
and Tilg-Zouari 2021). A total of 2,039 records
from the Indian Ocean can be found in the Ocean
Biogeographic Information System (OBIS) and
the Global Biodiversity Information Facility
(GBIF), of which 1,005 occurrences have been
reported so far, though other records may be
scattered throughout the literature and other bio-
geographic databases. This observation repre-
sents the blue button jelly P. porpita washed
ashore at Bheemunipatnam beach, and it is the
first record in Visakhapatnam coastal waters. In
addition, the present study discussed a detailed
description of the species, its distribution and the
negative impact of fishers.
On March 16th, 2021, a cluster of twenty
colonies of P. porpita were observed in Bheemu-
nipatnam village, Visakhapatnam (Western Bay
of Bengal). Out of twenty colonies, two P. porpita
specimens were transported for laboratory analy-
sis; later in the collection, specimens were exam-
ined visually and photographed. Specimens were
preserved in a 4% formaldehyde solution for fur-
ther anatomical studies. Anatomical details were
observed with a dissection microscope and
described following Ruppert et al. (2004) and Fox
(2007). Specimens were stored in separate glass
containers and deposited in the referral Museum
of Fishery Survey of India, Visakhapatnam.
The animal is a round, bright blue colour, float-
ing hydroid colony having a large, gas-filled flat
disc with a prominent central pore and numerous
minute pores radiating from the centre, no free-
floating sail, a single mouth beneath the float and
tentacles. The lower side of the disc has a small,
central gastrozooid with a terminal mouth and is
surrounded by many gonozooids, and dactylo-
zooids extending towards the periphery (Figure 1).
The hydroid colony has a large, disc-shaped
mantle and it floats on waters surface. Polyps and
tentacles are finger-like projections that are sub-
merged on the underside of the water. The upper-
side is slightly convex, without tubercles, and the
central portion has a round elevation where a
small central pore (stigmata) is present. Upper
float and hanging polyps are present; there is a
large central mass made up of mesoglea penetrat-
ed by tubular, gastrodermal extensions. The cen-
tral region is hardened due to an internal chitinous
float (pneumatophore) containing a series of con-
centric air chambers with pores on the upper side.
The central part of the organ is covered by ecto-
dermal tissue and filled with cnidoblasts, which
are located between the upper and lower portion
of the central mass. The cnidoblasts drift to tenta-
cles and polyps, where they become stinging cells.
The colony is divided into three sections: a large
central gastrozooid, a median band of numerous
gonozooids, and a peripheral band of dactylo-
198 MARINE AND FISHERY SCIENCES 36 (2): 197-202 (2023)