DOI

https://doi.org/10.34331/cpops.2022S001

J-STAGE Advance published date: June 6, 2023

CRANIAL MEASUREMENTS OF A STRANDED BRYDE’S WHALE FROM KUWAITPRELIMINARY REPORT ON THE CRANIAL
MEASUREMENTS OF A BRYDE’S WHALE STRANDEDIN FAILAKA ISLAND, KUWAIT IN 2014
Gen NAKAMURA1*, Abdullah AL-ZAIDAN2, Manaf BEHBEHANI3 andHidehiro KATO1, 41

Laboratory of Cetacean Biology, Tokyo University of Marine Science and Technology,
4–5–7 Konan, Minato-ku, Tokyo, 108–8477, Japan
2Kuwait Environment Public Authority (EPA), P.O. Box: 24395, Safat 13104, Kuwait
3Kuwait Science Company, P.O. Box 56 Dasman, State of Kuwait 15451
4
Institute of Cetacean Research, Toyomi Shinko Building 5F, 4–5 Toyomi-cho,Chuo-ku, Tokyo, 104–0055, Japan*Corresponding author: gnakam1@kaiyodai.ac.jp

Abstract
On 28 February 2014, a dead baleen whale was stranded and found by residents on the east
coast of Failaka Island, Kuwait. The specimen was a female with a total length of 14 m. Aftermuscle and internal organ removal and sample collection, the remains of this animal wereburied in situ. The Japanese authors of this paper visited Failaka Island to check the conditionof the skeleton after about nine months since the stranding event. A total of 44 measurements,including condylobasal length, were made from the dorsal side of the skull. Skull length was
3.222 m, which represented 26.85% of the body length. The skull of the specimen possesses
diagnostic characteristics of Bryde’s whale, such as the outer edge of the rostrum being rounded and ﬂattened in dorsal and lateral views, respectively. The number of ribs were 13 on theleft, and 12 on the right side. The skeleton was reburied to allow natural decomposition of theremaining soft tissue. As of 2022 we have not been able to excavate this skeleton, but we hope
to do so in the near future and hope the specimen will be properly catalogued and permanently
stored at some museum or institution in Kuwait.
Key words:

Skeletal measurement, Balaenopteridae, Bryde’s whale, Balaenoptera edeni
morphometric, large whale.

The Bryde’s whale Balaenoptera edeni Anderson, 1879, is a medium-sized balaenopterid with a
total length of about 13 to 15 meters. While most baleen whales have a clear seasonal migration andantitropical distribution, the Bryde’s whale inhabits tropical and warm temperate waters of the Indian,Paciﬁc, and Atlantic Oceans of 40°N to 40°S with a circannual water temperature of 16.3°C or warmer(Kato and Perrin, 2018).
Two genetically and morphologically distinct populations exist within this species, namely B. edeni
brydei (Olsen, 1913) and B. edeni edeni (Committee on Taxonomy, 2022). Balaenoptera e. brydei islarger and inhabits oﬀshore waters, whereas B. e. edeni is smaller and found closer to shore (Wadaet al., 2003; Sasaki et al., 2006; Kanda et al., 2007; Kato and Perrin, 2018; Committee on Taxonomy, 2022). In recent years, some scientists have suggested that these two populations should be separated at the species level and named as B. brydei and B. edeni, but no agreement has been reached yet(Rosel et al., 2021). In 2021 Bryde’s-like whales from the northern Gulf of Mexico were described asa new species, B. ricei (Rosel et al., 2021).
Morphological information, such as external and skeletal characteristics, is one of the essential taxonomical traits along with genetics to determine cetacean species. However, for large whales such as
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21NAKAMURA, AL-ZAIDAN, BEHBEHANI AND KATO

Bryde’s whales, the number of available skeletal specimens is small and makes a signiﬁcant challenge
for taxonomic studies. Although several sightings and strandings of Bryde’s whale have been reported
from the Arabian Sea and adjacent waters, the number of skeletal specimens of this species is limited.
Only ﬁve skeletal remains of Bryde’s whale have been reported from the Iranian coast of the Arabian (Persian) Gulf and the Gulf of Oman since 1971 (Braulik et al., 2010). Some of the other Bryde’s
whales strandings from the Arabian (Persian) Gulf include the following: (1) a 12.5 m male stranded atQasr, Iraq on 5 February 1967 (Al-Robaae, 1967, Mahdi, 1967), (2) a 14.5 m individual stranded near
the ARAMCO causeway at Abu Ali Island, Saudi Arabia in March 1995 (Robineau and Fiquet, 1996),and (3) a dead specimen stranded in May 1995 at the Saudi Arabia-Bahrain causeway (Robineau andFiquet, 1996).
Stranding events are the only way of obtaining skeletal specimens of large whales in areas wherewhaling is not conducted. However, especially in the case of large whales, they are not always collected from all stranded animals due to the high cost of cleaning, preparing and maintaining such skeletal
specimens and the problem of securing storage space. Therefore, the number of scientiﬁcally valuableskeletal specimens available for academic research is limited.
In early 2014, a baleen whale was stranded on Failaka Island in Kuwait. This animal was buried
after being examined by local scientists. About nine months later, following the request of a Kuwait
scientiﬁc institute to make a skeletal specimen, the whale carcass was temporarily dug out to verify its
conditions and to conduct preliminary research on skeletal measurements by Japanese researchers. Asof 2022, the skeleton has not yet been excavated for various reasons. However, the data obtained fromour brief examination are valuable to further understand the ecology of the Bryde’s whale. Therefore,
they are provided in this preliminary report.

Fig. 1. Location of the Bryde’s whale that stranded in 28th February, 2014. a) Wider area map, around theArabian (Persian) Gulf. b) Map showing the position of Kuwait and Failaka Island. c) Failaka Island map. The
black circle indicates the Bryde’s whale stranding location.

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CRANIAL MEASUREMENTS OF A STRANDED BRYDE’S WHALE FROM KUWAIT

Fig. 2. December 2014 excavation of the Bryde’s whale to check the skeletal conditions and to conduct scientiﬁc observations.

Fig. 3. Cranial measurement points and values of the Bryde’s whale stranded in Failaka Island, Kuwait, inFebruary 2014. a) and b) dorsal view, c) caudal view, d) dorsal view of the vertex, and e) lateral view of theskull. For measurement point explanation and values, see Table 1.

On 28 February 2014, a dead baleen whale was found stranded by residents on the east coast ofFailaka Island (29°24′50.9″N, 48°23′44.86″E), Kuwait. This island is located about 20 km oﬀ the coastof Kuwait City, in the northern part of the Arabian (Persian) Gulf (Fig. 1). In response to the stranding
report, on 1 March 2014 Kuwaiti researchers visited the site to examine the carcass and to make anassessment on the possible causes of the whale’s death. After their conducting external measurements
followed by autopsy and examination of the internal organs, this animal was initially identiﬁed as a ﬁn
whale having a body length of 14 m (Khalaf, 2014). After sample collection and removal of muscles
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NAKAMURA, AL-ZAIDAN, BEHBEHANI AND KATO

Table 1.
No.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.

Cranium measurements of the Bryde's whale stranded in Failaka Island, Kuwait, in 2014.
Measurement points

cm

Condylobasal length
Length of rostrum
Length of premaxillary (L)Length of premaxillary (R)Length of maxillary (L)Length of maxillary (R)Tip of premaxillary to tip of maxillary (L)Tip of premaxillary to tip of maxillary (R)Tip of premaxillary to nares, anterior
Tip of premaxillary to vertex
Breadth of maxillary, posterior edge
Breadth of premaxillary, posterior edge
Breadth of rostrum at base
Breadth of premaxillary at base
Breadth of rostrum at middle
Breadth of premaxillary at middle
Greatest breadth of premaxillary
Breadth of cranium, maxillary
Breadth of cranium, middle of orbital foramen
Breadth of cranium, anterior edge of zygomatic process
Breadth of cranium, middle of zygomatic process
Breadth of occipital bone
Length from upper ridge of foramen magnum to superior part of occipital bone
Minimum breadth of parietal bone
Length of nasals
Breadth of nasals, anterior
Breadth of nasals at middle
Breadth of nasals, posterior
Height of foramen magnum
Breadth of foramen magnum
Breadth across occipital condyles
Breadth of occipital condyle (L)Breadth of occipital condyle (R)Height of occipital condyle (L)Height of occipital condyle (R)Breadth of orbit (L)Breadth of orbit (R)

322.2
209.1
245.7
246.7
227.5
227.5
20.0
19.7
224.2
248.7
23.6
17.4
90.5
29.3
63.3
28.8
34.2
135.6
134.8
146.6145.6
97.0
71.4
23.4
22.2
17.6
13.1
5.8
10.0
7.3
25.6
11.3
11.4
17.4
18.2
24.0
23.3

and internal organs, the remaining parts of the animal were placed in a pit four to six meters deep andburied in the sand.
From 20 to 22 December 2014, the authors of this paper visited Failaka Island to unbury and checkthe skeleton’s condition and to obtain photographic and measurement records (Fig. 2). The left ﬂipper
was ﬁrst excavated. The orientation of ﬁnger bones was photographed and traced with a clear plastic
sheet. The soft tissue was almost decomposed and liqueﬁed but still remained within the ﬁnger bones.
As regards the rest of the skeleton, the residual muscle and fatty tissue had not completely decomposed and were still remaining, especially at the underside of the bones. Ribs, cervical, and dorsal ver-24

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CRANIAL MEASUREMENTS OF A STRANDED BRYDE’S WHALE FROM KUWAIT

Fig. 4. Dorsal (a) and lateral (b) view of the skull. Note that ventral part of the skull is ﬁlled with sand. The
scale bar indicates 1 meter.

tebral bones were assigned numbers and labeled with plastic tags. The remnant bones (right ﬂipper’s,vertebrae, ribs, and chevrons) were also collected. Measurements and photographic records were taken of the skull for the purpose of academic use before burying them again. Except for the pelvic bones
and some (maybe three to ﬁve) tips of the right ﬁnger bones and the left tympanic bulla, all skeletal
parts have been collected. About 17 neural spines of the dorsal and lumbar vertebras were broken.
This would probably have been caused by the following reasons: ﬁrst, that the spines were also decaying within the ﬂesh, which was not removed completely. And a second reason may be the neuralspines’ position, which stayed level and under pressure from the above sand.
A total of 44 measurements, including skull length, were taken from the dorsal side of the cranium.
The skull length (condylobasal length) was 3.222 m, which represented 26.85% of the specimen’sbody length (Fig. 3, Table 1). Omura (1959) compared the osteological characteristics of Bryde’s andsei (B. borealis) whales. The skull shape of the animal possesses diagnostic characteristics of Bryde’s
whale, such as the outer edge of the rostrum being rounded and ﬂattened in dorsal and lateral view, respectively, which was reported by Omura (1959) (Fig. 4). Numbers of ribs were 13 and 12 in left andright, respectively. The 13th left rib was separated into two pieces (not broken). The vertebral formula
was as follows:

C7 + D13 + L13 + Ca17 + α .
After measuring and photographing the skull, the skeletal pieces were transported from Failaka
Island to a protected area on mainland Kuwait and buried again. This will allow the remaining soft
tissues still attached to the bones to decompose so that a skeletal specimen of this animal may be prepared later on. We hope to do so in the near future so that this scientiﬁcally valuable specimen may bepermanently stored in a museum or another appropriate institution in Kuwait.
We would like to express our appreciation to everyone who coutributed to this mission, including
the Kuwait Environmental Public Authority (EPA) personnel, the technical staﬀ of the Nishio BiologiCetacean Popul. Stud. (CPOPS), Short noteVol. 4, 2023, 21–2625

NAKAMURA, AL-ZAIDAN, BEHBEHANI AND KATO

cal Models, Co. Ltd., and the Sakamoto Taxidermy Studio of Kyoto, Japan.

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Received: October 14, 2022
Accepted: March 9, 2023
Published online: June 6, 2023

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