1. A specimen of the heart urchin Maretia planulata was collected off the coast of Thoothukudi, India and represents a new record for the region. 2. M. planulata is widely distributed throughout the Indo-Pacific but has not previously been reported from western India. 3. The specimen was identified based on characteristics that distinguish M. planulata from similar species, including shallow frontal sinus, oval subanal fasciole, and extension of primordial plates.

1. International Journal of Marine Science 2015, Vol.5, No.32, 1-3
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A Letter Open Access
Note on the Genus maretia gray, 1855 and Description of Maretia planulata
(Lamarck, 1816) (Echinoidea, Spatangoida), off Thoothukudi Coast of Gulf of
Mannar, India (08º 35’22.5” N 78º 27’40.9 E) – (310 M)
T. Vaitheeswaran , T. Rajasekaran, S. Balasubramani
Rarbio Energies Private Limited, Department of New Drug Discovery (Marine Division), #311/2, Vellalar Street, Mel Ayanambakkam, Chennai- 600 95, Tamil
Nadu, India
Corresponding author email: fdre@rarbio.com
International Journal of Marine Science, 2015, Vol.5, No.32 doi: 10.5376/ijms.2015.05.0032
Received: 20 Mar., 2015
Accepted: 06 May., 2015
Published: 20 May., 2015
Copyright © 2015 Vaitheeswaran et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Vaitheeswaran et al., 2015, Note on the Genus maretia gray, 1855 and Description of Maretia planulata (Lamarck, 1816) (Echinoidea, Spatangoida), off
Thoothukudi Coast of Gulf of Mannar, India (08º 35’ 22.5” N 78º 27’ 40.9 E) – (310 M), International Journal of Marine Science, Vol.5, No.32 1-3 (doi:
10.5376/ijms.2015.05.0032)
Abstract Heart sea-urchin was collected from Thoothukudi coast of Gulf of Mannar, Southeast coast of India on April 11, 2014.
This specimen was classified as Maretia planulata (Lamarck, 1816) belonging to the family Spatangidae. The most speciose echinoid
orders, Spatangoida and Clypeasteroida, are abundant in the Indo-West Pacific and Caribbean. This genus and species are newly
recorded in two distinct Indo-Pacific marine zones. One specimen was caught at the depth of 310 m as an incidental by-catch. It was
found in tropical waters from about 08º 35’ 22.5”N 78º 27’ 40.9 E/310 m from Thoothukudi fishing harbour, southeast coast of India.
This species inhabits tropical waters and usually distributed over the West Pacific from southern Japan to Australia.
Keywords Spatangidae; Maretia planulata; First record; Thoothukudi coast; Gulf of Mannar
Introduction
The genus Hemipatagus was established in 1858 by
Desor for the species Spatangus hoffmanni Goldfuss,
1829. Subsequently, Agassiz (1873) placed
Hemipatagus is synonymy with Maretia Gray, 1855.
Heart sea-urchins represent the largest group of
irregular echinoids. There are well over 200 living
species assigned to some 60 genera representative of
10 families, occurs in the Indo-West Pacific. Heart
sea-urchin is capable of burrowing and living within
most sediments, hence their worldwide distribution
(Joe Chiold, 2013). Individual geographic ranges
worldwide are illustrated in map form for 414
echinoid species. Few forms show widespread ranges,
the exceptions being Metalia sternalis, Brissopsis
luzonica, Brissus latecarinatus, Metalia spatangus,
Maretia planulata, and Echinocardium cordatum (Joe
Chiold, 2013). The East Indian Ocean harbors a rich
array of heart sea-urchin forms. Thirty-five or more
species occur here representing over 20 genera from
seven families.
Mortensen (1951) noted that the presence of ampullae
was not verified in the type species of Hemipatagus.
The other two features listed by him were: 1. a more
heart shaped outline with deeper frontal notch. 2. The
broader, bilobed subanal fasciole in Hemipatagus.
Smith (2004) noted the high similarity between
Hemipatagus and Lovenia and proposed its inclusion
in the Loveniidae. Apparently there are no records
from Western India, Pakistan, the Persian Gulf or the
Indian coast of the Arabian Peninsula. In view of this
the colouration differences noted by Mortensen (1951)
may be more meaningful than he considered they were.
He described a whitish to yellow colouration in Indian
Ocean populations, verus Malayan specimens, which
are usually dark.
Spatangoids are echinoids characterized by their
bilaterally summetrical corona and highly modified
ambulacra forming a complex respiratory apparatus.
They are well adapted to a life as burrowers and
ploughers in mobile sediments, exploiting organic
detritus as their prime food resource. Indeed,
spatangoid phylogeny and higher-rank taxonomy
has been heavily reliant on fascioles. These are
narrow bands of small ciliate spines secreting
mucus that consolidated the walls of their burrows
and protects the respiratory tube feet from fine mud
(Lawrence, 1987).

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Spatangus planulatus Lamarck, 1816, p. 326
Spatangus (Maretia) perornatus Schaffer, 1912: 190-1;
pl. 59, fig. 4-6
Maretia perornata, Schaffer, 1912: 596; pl. 1, fig. 5-6
M. planulata Ali, 1985: 294-295; figs 12 A-B
M. ranjitpurensis Jain, 2002: 130-132; pl. 6, figs. 11-14
M. carolinensis Kier, 1997: 11-13; fig. 6; pl. 9, figs
8-9; pl. 10, figs. 1-7; pl. 11, figs. 1-2
1 Material
Measuring 8.3 cm total length and 15 g weight (Figure
1 and 2)
2 Locality
08º 35’ 22.5”N 78º 27’ 40.9 E off Thoothukudi coast
of Gulf of Mannar, Southeast coast of India; depth at
trawling 310 m.
3 Description
Maretia planulata, the frontal sinus is shallower and
often indistinct 2. The labrum is much narrower and
more elongated 3. The Posterior end is bluntly pointed
not transversely truncated 4. Even in large specimens
the primary tubercles do not develop true ampullae or
strongly sunken areoles. Especially not on the oral
surface 5. The plastron is much more strongly
constricted between the first and second pair of
episternal plates (Figure 1) 6. The outline of the test is
oval, antero-posteriorly elongated, not cordiform 7.
The subanal fasciole is oval and rather high instead of
bilobed, very wide and low 8. The labrum and the
primordial plates of the interambulacra extend much
further 9. There are phyllodal pores (14-15) in
ambulacra II and IV (only 6-7 in H. hoffmanni) 10.
Figure 1 Dorsal view – Maretia planulata
Ambulacra II and IV are only slightly constricted
ambitally, whereas they are strongly constricted in H.
hoffmanni.
4 Remarks
Extant species of Maretia, principally M. planulata,
are currently considered to occur in two distinct
Indo-Pacific marine zones. Maretia differs by
possessing an extremely shallow frontal notch, the
distribution of the aboral primary tubercles (primary
tubercle reach the tips of the posterior pairedpetals), the
lack of strongly sunken areoles or camellate aboral and
oral primary tubercles, the strongly crenulate nature of
the aboral primary tubercles, the lack of a conspicuous
field of coarse tubercles in adapical interambulacral
columns 2b and 3a, its oval ‘t’ shield-shaped subanal
fasciole, the longer primordial plates of the paired
interabulacra (Figure 1 and 2) which extend to the third
or fourth ambulacral plates of the adjacent ambulacra
in Maretia, while they do not extend the second
ambulacral plate in (Hemipatagus or Lovenia), the
labrum which extends to the third or fourth ambulacral
plate (not extending beyond) the second ambulacral
plate in Hemipatagus and Lovenia and the less
constricted adoral ambulacra 2 and 3 (Figure 1).
5 Distribution
Extant species of Maretia, principally M. planulata,
are currently considered to occur in two distinct
Indo-Pacific marine zones: From southern India and
Figure 2 Ventral view – Maretia planulata

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Sri Lanka, eastwards across the Indo-Malayan
Archipelago, Indonesia, the Philippines, Papua New
Guinea, north and east Australia, and western Pacific
Islands from Japan in the north to Fiji and New
Caledonia in the south, and as far east as Hawaii. This
latter species is the most widely distributed of the
spatangoids; it can be found in nearly all major oceans,
but it is absent from the mid-Atlantic, North Australia,
and the East Indies. A little over half of the Indo-West
Pacific species are endemic. This is true particularly
among the families Brissidae, Spatangidae, Lovenidae
and Pericosmidae. M. planulata Indonesia (Mortensen,
1951), M. planulata Papua New Guinea (Lindley,
2003), M. planulata South Sea Islands (Nisiyama,
1968), Maretia sp. New Zealand (Henderson, 1975),
Agassizia aequipetala United Kingdom (Gregory,
1891).
Author’s Contribution
Vaitheeswaran Thiruvengadam have been collected and
identification of specimen and took photograph of specimen
and reference collection. Rajsekaran T, Managing Director of
RARBIO Energies Pvt Ltd, Financial support of Marine
Invertebrate Division and Marine Pharma division, Chennai,
India. Balasubramani S, Director of RARBIO Energies Pvt Ltd.,
conceived of the study, help and support of Fishing landing
centre, Chennai, India.
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