The biodiversity of the class Ascidiacea in the Gulf of ...taxonomy.tau.ac.il/.upload/Shenkar ITI report 10_12_14 Final.pdf · Biodiversity of ascidians in the Gulf of Eilat/Aqaba

Biodiversity of ascidians in the Gulf of Eilat/Aqaba Koplovitz & Shenkar

December 2014

1

The biodiversity of the class Ascidiacea in the Gulf of Eilat (Aqaba)

Dr. Gil Koplovitz1,2, Dr. Noa Shenkar1

1 Department of Zoology, Faculty of Life Sciences, Tel Aviv University

2 Inter-University Institute for Marine Sciences in Eilat

[email protected], [email protected]

Ascidians (Phylum: Chordata, Class: Ascidiacea) are sessile, soft bodied, filter

feeding organisms that occur in solitary and colonial forms in all the world’s oceans.

They represent important components of food webs in a variety of benthic marine

communities (Monteiro et al., 2002; McClintock et al., 2004; Tatian et al., 2005). The

group comprises approximately 3000 species found in all marine habitats, from polar

regions to tropical coral reefs (Shenkar and Swalla, 2011). Since the end of the 20th

century, ascidians have gained much interest in different fields of research. Ascidians are

considered the closest living representative of the ancestral chordate, therefore, they have

been extensively studied in the fields of evolutionary and developmental biology,

immunology, as well as natural products chemistry, for their potential use in the

pharmaceutical industry (Reviewed in Shenkar and Swalla, 2011). In recent years,

ascidians have received increasing attention due to their negative impact as invasive

species and the ability of native species to thrive in nutrient rich (eutrophic)

environments, often resulting in catastrophic effects on the local indigenous fauna

(Monniot et al., 1991; Bullard et al., 2007; Lambert, 2007).

The coral reefs of the Red Sea represent a hotspot for endemism and biodiversity,

making them a high priority for conservation (Roberts et al., 2002). Despite the increased

attention ascidians have received in recent years, the ascidian fauna along the Israeli coast

of the Red Sea is still largely understudied. To date, there are only 73 described ascidian

species from the Red Sea, with less than half of those species present at the National

Collections of Natural History at Tel Aviv University (Shenkar, 2012)

mailto:[email protected]

mailto:[email protected]


December 2014

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Our original proposal to the Israel Taxonomy Initiative was designated to enhance

the study of ecological, physiological and morphological aspects of ascidians along the

Israeli coast of the Red Sea, and included the following objectives:

RESEARCH OBJECTIVES

1. To conduct a comprehensive survey of the ascidian fauna in the Gulf of Eilat

along a spatio-temporal gradient.

2. To morphologically identify the ascidian species collected.

3. To obtain COI sequences for molecular identification of the collected species.

MATERIALS AND METHODS

The current ascidian collection in the National Collections of Natural History at

Tel Aviv University constitutes a unique collection in that all specimens feature dual

preservation- in formaldehyde for classic morphological identification, and in absolute

ethanol for molecular work. In order to enlarge the ascidian collection, extensive

periodical field surveys have been performed along the coast of Eilat on the natural coral

reefs and on man-made submerged structures. The extensive surveys took place from

October 2012-October 2014 in multiple locations along the Red Sea coast in order to

record both the spatial and temporal distribution patterns of the ascidian fauna (Table 1).

Ascidians were dissected and identified using authoritative taxonomic keys and texts,

catalogued, and preserved in both formaldehyde and absolute ethanol. All ascidian

specimens have been deposited in the Steinhardt National Collections of Natural History,

TAU. A major part of the survey took place at depths of 30-60 m, in an area that has not

been surveyed for ascidians to date. Preliminary collecting from this zone revealed an

unknown population of ascidians, including new species to science. For this purpose, Dr.

Gil Koplovitz have been trained in technical diving under the scope of the grant.

Technical diving allows the surveys at these depths to be performed for longer periods of

time than standard SCUBA dives, hereby enabling a more comprehensive survey, as

many of the ascidians in this region are cryptic and require close examination of

underwater structures as well as turning over of rocks and corals in order to discover

them.


December 2014

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In addition, during the summer of 2014 we have initiated the "Ascidian

Biodiversity Campaign" (ABC). Our aim was to incorporate both recreational and

scientific divers’ observations and photos to establish a database of new and known

ascidians in the Gulf of Aqaba, along the coasts of Israel and Jordan in the future.

Encouraging local divers to participate in the sampling effort will help us in the future to

increase our data and collect species that have been unnoticed before. As part of the ABC

we conducted a public event at the Inter-University Institute in Eilat in July 2014 focused

on ascidian biodiversity and taxonomy. At this public event which gathered

approximately 50 people, we distributed under-water field guides (Figure 1a.b) of the

dominant solitary and colonial ascidians of the area. Our request from the divers was to

send us photos of ascidians that do not appear in the guide specifying the following

information: date, name of photographer, site, depth, substrate type (artificial or natural,

sand or reef, etc.). In addition, we distributed in diving clubs in Eilat informative posters

(Figure 2). The purpose of the posters are to raise public awareness to this unique group

of invertebrate and promote our ABC project. In order to learn how many different

Figure 1. Ascidian Biodiversity Campaign (ABC) underwater ascidian identification field

guides. These field guides were distributed among scientific and recreational divers in Eilat.


December 2014

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ascidian species occur in the region, and quantify how many have been identified and

occur in the collection, we conducted a rapid taxonomic assessment based on all ascidian

photos collected.

RESULTS

1. Ascidian collection status at the Steinhardt National Collections of

Natural History.

There are currently 127 ascidian specimens from the Gulf of Eilat in the National

Collections of Natural History at TAU which have been collected since October 2012, of

which 47 have been identified to genus level only.

Figure 2. Ascidian Biodiversity Campaign (ABC) informative poster. The poster have been

distributed in diving clubs in order to encourage recreational divers to send us ascidian

photos for our rapid assessment project.


December 2014

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2. Comprehensive ascidian survey

A total of 65 survey dives were performed along the Israeli coast of the Gulf of Eilat, in

numerous locations between the Jordanian and Egyptian borders (Table 1, Fig. 3).

Rapid assessment of the number of different ascidian species in the Gulf of Aqaba

revealed the occurrence of approximately 60 different species of colonial (56%) and

solitary (44%) species.

Figure 3. Survey dive locations along the Israeli coast of the Gulf of Eilat. Numbers in

parentheses represent the number of ascidian species recorded at each location.

Table 1: Underwater surveys performed in the Gulf of Eilat between October 2012

and September 2014.

Date of survey Site Survey

duration

Survey depth

(m)

Dominant

substrate in site

28/12/2012 Igloo 59 13.7 Artificial

31/12/2012 Kisusky Snorkeling Artificial

15/01/2013 Electricity Beach (Navy) 47 27.2 Natural

30/01/2013 IUI 46 15.5 Artificial

31/01/2013 Princess 48 21.7 Natural

05/02/2013 Diver's village 57 25.2 Natural


December 2014

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07/02/2013 Japanese Gardens 69 15.5 Natural

11/02/2013 Tour Yam area 43 19.3 Natural

19/02/2013 Nature reserve 47 14.7 Natural

20/02/2013 Electricity Beach (Navy) 51 14 Artificial

20/02/2013 Dekel Beach Natural

11/03/2013 IUI 64 12 Both

17/03/2013 SNUBA 38 21.8 Natural

04/04/2013 IUI 37 13 Artificial

09/04/2013 IUI 64 20 Both

22/04/2013 IUI 46 33.5 Both

23/04/2013 Pyramid 39 29.9 Artificial

24/04/2013 Underwater restaurant 69 11.3 Artificial

24/04/2013 Diver's village 44 27.1 Natural

25/04/2013 Satil 41 25 Artificial

29/04/2013 Observatory wall 53 27.1 Natural

29/04/2013 Dekel 37 31.7 Both

01/05/2013 Observatory wall 56 13.7 Both

02/05/2013 Oil Port 46 18.3 Artificial

05/05/2013 IUI 55 32.6 Artificial

06/05/2013 Satil 53 23.4 Both

07/05/2013 IUI 45 8 Artificial


29/05/2013 IUI 40 12.2 Artificial

03/06/2013 Tamar Reef 58 8.5 Artificial


06/06/2013 IUI 43 32.9 Natural

18/06/2013 IUI 45 15 Both

27/06/2013 IUI 55 32.6 Natural

01/07/2013 Satil + Paradise 60 30 Both

23/07/2013 Tamar Reef 63 8.2 Both

24/07/2013 IUI 61 16.5 Both

25/07/2013 Oil Port 60 12 Both

11/08/2013 IUI 56 30.8 Natural

20/08/2013 SNUBA 55 18 Natural

22/08/2013 Coral Beach 53 29.3 Natural

22/08/2013 Tamar Reef 64 9.1 Artificial


26/08/2013 Sunboat 73 16.2 Artificial



December 2014

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01/09/2013 Dolphin reef net 67 18.9 Artificial

02/09/2013 Dekel 30 Both

18/03/2014 Coral Beach 50 12 Natural




19/03/2014 Princess 45 12 Natural

19/03/2014 Princess 25 Natural




20/05/2014 Aroma restaurant 32 5.5 Artificial

14/07/2014 Sunboat 42 21 Artificial

29/07/2014 Satil 50 24.7 Artificial

30/07/2014 Paradise 47 28.7 Natural

31/07/2014 "Yatush" wreck 44 32.1 Both

27/08/2014 Tour Yam area 70 16 Natural

28/08/2014 Amphibious vehicles 16 Artificial

14/10/2014 IUI 16 33 Both

30/10/2014 Oil Port 17 45 Artificial

Analysis of results. The most common ascidian, observed in 97% of survey dives, was

Polycarpa cryptocarpa, followed by Didemnum spp. (Fig. 4). Ascidians of the family

Didemnidae are very difficult to identify to species level in situ, and the observed

Didemnids likely belong to several different species.


December 2014

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The highest number of species was recorded in the reef in front of the Inter-University

Institute of Marine Sciences (IUI) and the adjacent nature reserve (Coral Beach). These

are also the locations where the most survey dives took place (14 survey dives in IUI and

10 in the nature reserve) (Fig. 6). This raises the issue of sampling effort, and the current

survey demonstrates that the number of species discovered in a location increases with

the number of surveys performed in each location (Fig. 7).

The number of different species observed in a dive site with mostly artificial habitats

(such as wrecks or jetty pillars) was slightly higher than in natural habitats (Fig. 5),

however the difference was not statistically significant (p>0.05, ANOVA).

When comparing the north beach (From Dekel Beach to border with Jordan) to the

southern beach (from the Dolphin Reef to the border with Egypt), there is a similar

average number of species encountered in a dive (6.42 and 6.94, respectively), the

average number of species in the north beach region is lower than the south beach region

Figure 4. Observed frequency (percent of dives in which a species was observed) of the common ascidian

species during survey dives in the shallow (0-30m) reef in the Gulf of Eilat.


December 2014

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(8.67 vs 15). Out of the 25 most common ascidians (Fig. 4), the north beach contained

only 16 species compared with all 25 species found in the south region.

Figure 5. Number of species encountered in a single dive in different habitats.

Figure 6. Number of species recorded and number of survey dives performed at different

locations along the Israeli coast of the Gulf of Eilat.

0

1

2

3

4

5

6

7

8

9

Artificial Mixed Natural

Nu

mer

of

spec

ies

ob

seve

d in

a d

ive

(mea

n +

S.

E.)

Dominant subsrate in dive site


December 2014

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Figure 7. Relationship between number of survey dives in a location and the number of

species recorded in that location.

Surveys of the mesophotic area (30-60 m depth).

As stated in the proposal, a major part of the survey was planned to take place at depths

of 30-60 m, in an area that has not been surveyed for ascidians to date. Throughout the

year, Dr. Gil Koplovitz has completed training in technical diving, and has conducted

extensive surveys in the mesophotic zone of the coral reefs (table 2).

Figure 8. Dr. Gil Koplovitz performing a survey at 60m depth using trimix diving

(photo: T. Shlesinger).

y = 1.1454x + 6.968

R²=0.8502

0

5

10

15

20

25

0 5 10 15

# sp

ecie

s

# dives


December 2014

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Table 2: Underwater mesophotic surveys performed in the Gulf of Eilat between October

2013 and September 2014 using technical diving.

Survey date Site Survey duration Survey depth

(m)

Dominant

substrate in site

19/12/2013

IUI - south of

habitat 74 42 Natural

22/12/2013

IUI - south of

habitat 67 46 Natural

23/12/2013

Lighthouse

beach 53 46 Natural

25/12/2013 Oil port 77 48 Natural


22/01/2014

Japanese

Gardens 67 45 Natural

23/01/2014

Japanese


26/01/2014

Japanese


28/01/2014 IUI 50 46 Natural

26/02/2014 IUI 46 41 Natural

14/05/2014 Diver's village 59 43 Natural


02/06/2014 IUI 51 35 Natural


16/09/2014 IUI 45 42 Natural

17/09/2014 IUI 55 50 Natural

18/09/2014 IUI 52 60 Natural

30/10/2014 IUI 75 60 Natural

Analysis of results. The species composition in the mesophotic reef is quite different in

the shallow reef, although the most commonly observed ascidian in these depths is still

Polycaroa cryptocarpa (found in 83% of the dives) followed by Rhopalaea idoneta

(found in 63% of the dives)(Fig.9). However, the most abundant ascidian in the

mesophotic reefs surveyed is Rhopalaea idoneta (Fig. 10). The number of species and

individuals observed in the mesophotic reef is lower than in the shallow reef (Fig. 9)


December 2014

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Figure 9. Observed frequency (percent of dives in which a species was observed) of

the common ascidian species during survey dives in the mesophotic reef (30-60m)

in the Gulf of Eilat.

Figure 10. Ascidian species abundances in the mesophotic reefs of Eilat.


December 2014

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Due to the logistics involved with technical diving, the mesophotic surveys took place

only in the reefs around the IUI (From the Japanese Gardens to the beach across from the

Diver’s Village club) and in the Oil port. A comparison only of the two dominant species

(Polycaroa cryptocarpa and Rhopalaea idoneta) between those two locations shows a

reverse trend: in the reefs around the Oil Port Polycarpa dominated (87% Polycarpa:

13% Rhopalaea), whereas in the southern reefs Rhopalaea dominated (79% Rhopalaea:

21% Polycarpa). Didemnum granulatum, a conspicuous colonial ascidian due to its

bright red color, was quite abundant in the reefs around the IUI, but absent from the reefs

around the Oil Port.

Species identification

133 ascidian specimens have been collected since October 2012. Out of which 58 have

been preserved in both formalin and ethanol.

Based on the morphological identification we have performed so far, and the

photographic surveys conducted over the past two years, we have recorded 58

morphologically unique species in the Gulf of Eilat (Table 3). Unfortunately, for many of

the species of the family Didemnidae and the subfamily Botryllidae, identification can be

very challenging due to the size of the zooids, and the lack of quality taxonomic keys for

this family.

Table 3: ABC rapid assessment. Inventory of Gulf of Eilat ascidian species

photographed between October 2012 and September 2014

Species ID Photo date Site Depth Substrate Field

number

Ascidia sp. 1 07/04/2013 IUI 1m Under rock 7002

Ascidia sp. 2 25/07/2013 Oil port 3m Under rock 7045

Ascidia sp. 3 19/03/2014 Princess 5m Under dead

coral

7083

Ascidia sp. 4 18/02/2014 IUI 13m Artificial-under

plate

7076

Boltenia yossiloya 12/02/2013 IUI 50m Base of coral GK0002

Botryllid 1 07/04/2013 IUI 1m Under rock 7004


Botryllid 3 09/04/2013 IUI 20m On coral 7006

Botryllid 4 19/06/2013 Oil port 17m On coral 7030/7039


December 2014

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Botryllid 6 20/03/2014 Kisusky 0.5m

Artificial-on

floating dock

7097

Botryllid 7 17/04/2014 IUI 0.5m Under rock Not

collected

Botryllus eilatensis 28/01/2013 IUI 6m Artificial-IUI

nursery

Not

collected

Cnemidocarpa

margaritifera

23/07/2013 Tamar Reef 6m Artificial-

concrete

7036/7075

Didemnum granulatum 27/03/2013 IUI 30m On

coral/sediment

7031

Didemnum sp. 1 19/02/2013 Coral Beach 8m On coral GK0013

Didemnum sp. 2 14/02/2013 Dekel 45m On coral GK0011

Didemnum sp. 3 23/04/2013 Pyramid 29m Artificial-

pyramid

7009

Didemnum sp. 4 23/04/2013 Pyramid 29m Artificial-

pyramid

7010

Didemnum sp. 5 24/07/2013 IUI 15m On coral 7040

Didemnum sp. 6 11/08/2013 IUI 6m under rock 7050

Didemnum sp. 7 25/08/2013 IUI 4.5m Under rock 7051

Didemnum sp. 8 26/08/2013 Sunboat 15m On clam on

boat

7053

Didemnum sp. 9 26/08/2013 Sunboat 15m On Pyura

gangelion

7052

Didemnum sp. 10 01/09/2013 Dolphin reef 10m Artificial-net 7057



Didemnum sp. 13 16/06/2014 Oil port 45m On seagrass 7106

Didemnum sp. 14 17/03/2013 Snuba 5m Natural reef Not

collected

Didemnum sp. 15 22/09/2014 IUI 7m On coral Not

collected

Didemnum sp. 16 17/04/2014 IUI 0.5m Under rock Not

collected

Diplosoma simile 09/04/2013 IUI 14.4m On coral 7007

Diplosoma sp. 19/03/2013 Princess 5m Under dead

coral

7085/7086

Ecteinascidia sp. 25/07/2013 Oil port 3m Under rock 7046

Eusynstyela latericius

morph 1

24/04/2013 Underwater

restaurant

3m Artificial-metal

frame

7011


morph 2

25/04/2013 Satil 25m Artificial-metal

ship hull

7014


morph 2 - a

29/07/2014 Satil 21m Artificial-metal

chain

7107


morph 1- orange

18/06/2013 IUI 8m Artificial-metal

frame

7026


December 2014

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Halocynthia spinosa 20/02/2013 Dekel 8m Artificial-metal

frame

Not

collected

Herdmania momus 24/04/2013 Rhapsodia

restaurant - north

beach

0.5m Artificial-

concrete

Not

collected

Phallusia arabica 18/02/2014 IUI 12m Artificial-under

plate

7073

Phallusia

arabica/julinea

08/05/2014 IUI 5m Under rock 7104

Phallusia nigra 20/02/2013 Dekel 8m On coral Not

collected

Polycarpa cryptocarpa 20/02/2013 Hashmal beach

(near navy)

3m Artificial-metal

frame

GK0020

Polycarpa sp. 19/03/2013 Princess 8m Artificial-under

metal plate

7082

Polyclinum sp. 27/03/2014 Lighthouse beach 1m Under rock 7087

Pyura gangelion 24/04/2013 Underwater

restaurant

7m Artificial-metal

frame

Not

collected

Rhodosoma turcicum 18/02/2014 IUI 12m Artificial-under

plate

7074

Rhopalaea idoneta 12/02/2013 IUI 55m On rock GK0006

Styela canopus 15/04/2013 Kisusky 1m Artificial-on

floating dock

7008/7105

Unknown colonial 1 05/06/2013 IUI 5m Under rock 7023

Unknown colonial 2 27/05/2014 IUI 12m Artificial-under

plate

Not

collected

Unknown colonial 3 17/04/2014 IUI 0.5m Under rock Not

collected

Unknown solitary 1 17/02/2013 Oil port 50m Base of coral GK0012

Unknown solitary 2 20/02/2013 Dekel 3m On rock GK0015

Unknown solitary 3 07/04/2013 IUI 1m Under rock 7005

Unknown solitary 4 24/07/2013 Igloo 10m Artificial-metal

frame

7038

Unknown solitary 5 22/07/2013 IUI 1m Under rock Not

collected

Obtaining COI sequences for molecular identification of the collected species.

We have collected 66 specimens in pure ethanol for DNA analysis in the past 2 years

(October 2012-October 2014). We have so far sequenced the COI gene from 10

individuals from each of 2 morphs of the colonial ascidian Eusynstyela latericius, as well

as the partial 18S rDNA from five of each morph in order to assess whether the two

morphs represent two separate species. The manuscript is currently being prepared.


December 2014

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Additionally, we have sequenced the COI gene of 6 specimens of a photosymbiotic

didemnd ascidian, previously identified as Diplosoma modestum (Shenkar, 2012), as well

as the partial 18S rDNA from one specimen. Together with a morphological analysis and

comparison to the typo specimen of D. modestum, we have revised the species ID and

determined it is Diplosoma simile. The results of this analysis have been recently

published in Systematic and Biodiversity journal under the title: “Being Green in the Red

Sea - The Photosymbiotic Ascidian Diplosoma simile (Ascidiacea: Didemnidae) in the

Gulf of Aqaba" (Koplovitz et al., 2014).

DISCUSSION

Shenkar (2012) reviewed the literature concerning the ascidian fauna in the entire

Red Sea (1950km) and compiled an inventory list of 73 ascidian species belonging to 13

families. In this study we surveyed the entire Israeli coast of the Gulf of Eilat (from the

Jordanian border to the Egyptian border – approx. 11km) and recorded approx. 60

morphologically unique species belonging to 9 families. As mentioned above, the

identification of colonial ascidians from family Didemnidae, and subfamily Botryllidae is

quite challenging dues to a lack of proper taxonomic keys for the region, which is why

the number of species is only an estimation. In some cases, the ascidians sampled in early

expeditions to the Red Sea were misidentified, as was demonstrated in this study with the

common photosymbiotic didemnid ascidian which was identified as Diplosoma

modestum or Diplosoma virens and we have shown, using morphological and molecular

tools that is in fact Diplosoma simile (Koplovitz et al., 2014). The ascidian fauna of the

Israeli coast of the Gulf of Eilat consists of few very common ascidians (Fig. 4), but also

with many rare and cryptic species, many of those were found only under rocks and dead

coral skeletons and are rarely seen exposed on the natural reef.

The mesophotic reefs have only began to be available for exploration in recent

years, with advancements in technical diving equipment and expertise. This area still

pose a challenge for exploration, with most of the surveys done in these depths

concentrate on corals and fish. In the current study we, have ventured into the mesophotic

reefs of Eilat (30-60m depth) in search of ascidians. To the best of our knowledge, this is


December 2014

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the first time ascidians at a tropical mesophotic area are being surveyed. Our initial

surveys show a lower diversity and density of ascidians in these depths, however large

parts of the mesophotic reef consist of dense coral rubble, sponges and algae (Fig. 11)

which further limits the ascidian surveys at these depths.

Figure 11. A typical mesophotic reef in Eilat, demonstrating the difficulty of searching for

cryptic ascidian species. Photo was taken at 60m in front of the IUI by Gil Koplovitz.

The rarity and cryptic nature of ascidians in the reefs of Eilat make traditional ecological

survey techniques such as transects and quadrats not suitable for surveys, and therefore it

is also difficult to compare ascidian densities between locations and between substrates.

For example, our observations show that the solitary ascidian Herdmania momus is

uncommon in the natural reef environment, but very common on artificial habitats such

as floating docks and nets in the northern beaches. However, due to the lack of

quantifiable measurement of densities that works both on natural and artificial substrates,

a statistical analysis of this observation is challenging.


December 2014

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The number of species found in the current study demonstrate the importance of

extensive sampling efforts. The surveys performed under this studies recorded, in only

11km of coastline and 2 years, 82% of the total number of species discovered in the

entire Red Sea in almost 50 years. This study also demonstrates the importance of

training young researchers in taxonomy, as no other sampling technique (ROV, trawling,

dredging) is as efficient as a trained taxonomist in the field, using SCUBA equipment, for

discovering new and cryptic species.

We would like to thank the ITI for supporting this project and providing us the

opportunity to explore the ascidian fauna of the Gulf of Eilat, and venture into previously

uncharted territories in the mesophotic zone.

LITERATURE CITED

Bullard SG, Lambert G, Carman MR, Byrnes J, Whitlatch RB, Ruiz G, Miller RJ, Harris L,

Valentine PC, Collie JS, et al. (2007) The colonial ascidian Didemnum sp. A: Current

distribution, basic biology and potential threat to marine communities of the northeast

and west coasts of North America. Journal of Experimental Marine Biology and Ecology

342:99-108

Koplovitz G, Hirose E, Hirose M, Shenkar N (2014) Being green in the Red Sea-the

photosymbiotic ascidian Diplosoma simile (Ascidiacea: Didemnidae) in the Gulf of

Aqaba. Systematics and biodiversity doi: 10.1080/14772000.2014.978410

Lambert G (2007) Invasive sea squirts: A growing global problem. Journal of Experimental

Marine Biology and Ecology 342:3-4

McClintock JB, Amsler MO, Amsler CD, Southworth KJ, Petrie C, Baker BJ (2004) Biochemical

composition, energy content and chemical antifeedant and antifoulant defenses of the

colonial antarctic ascidian Distaplia cylindrica. Marine Biology 145:885-894

Monniot C, Monniot F, Laboute P (1991) Coral Reef Ascidians of New Caledonia. ORSTOM,

Paris

Monteiro SM, Chapman MG, Underwood AJ (2002) Patches of the ascidian Pyura stolonifera

(Heller, 1878): structure of habitat and associated intertidal assemblages. Journal of

Experimental Marine Biology and Ecology 270:171-189

Roberts CM, McClean CJ, Veron JEN, Hawkins JP, Allen GR, McAllister DE, Mittermeier CG,

Schueler FW, Spalding M, Wells F, et al. (2002) Marine Biodiversity Hotspots and

Conservation Priorities for Tropical Reefs. Science 295:1280-1284

Shenkar N (2012) Ascidian (Chordata, Ascidiacea) diversity in the Red Sea. Marine Biodiversity

42:459-469

Shenkar N, Swalla BJ (2011) Global Diversity of Ascidiacea. PLoS ONE 6:e20657

Tatian M, Antacli JC, Sahade R (2005) Ascidians (Tunicata, Ascidiacea): species distribution

along the Scotia Arc. Scientia Marina 69:205-214

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The biodiversity of the class Ascidiacea in the Gulf of ...taxonomy.tau.ac.il/.upload/Shenkar ITI report 10_12_14 Final.pdf · Biodiversity of ascidians in the Gulf of Eilat/Aqaba