Research Article |
Corresponding author: Fatemeh Nazari ( fateme.nazari@gmail.com ) Academic editor: Kai Horst George
© 2021 Fatemeh Nazari, Omid Mirshamsi, Pedro Martínez Arbizu.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Nazari F, Mirshamsi O, Martínez Arbizu P (2021) Tigriopus iranicus sp. nov., a new species of Harpacticidae (Copepoda, Crustacea) from Iran, with a redescription of T. raki Bradford, 1967. ZooKeys 1035: 115-144. https://doi.org/10.3897/zookeys.1035.61584
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The first representative of Tigriopus Norman, 1869 from the north-western Indian Ocean is described from rock pools on the Iranian coast. Tigriopus iranicus sp. nov. is distinguishable from its congeners by i) the possession of two maxillary endites, each with two setae; ii) a two-segmented mandibular endopod; iii) P1 enp-3 with one pinnate claw, a well-developed geniculate spine and a small seta; and iv) female P6 with two setae. Additionally, we present a complete redescription of Tigriopus raki Bradford, 1967 on the basis of paratype material and a key to the species of the genus.
Harpacticoida, meiofauna, Oman Sea, Persian Gulf, rocky shore, splash pool, taxonomy
The genus Tigriopus was introduced by
At present, the genus Tigriopus includes 15 valid species with wide geographical distributions. They inhabit rock pools of Macquarie Island (T. angulatus Lang, 1933), Angola (T. brachydactylus Candeias, 1959), the North Atlantic Ocean (T. brevicornis Müller, 1776), the Pacific coast of North America (T. californicus Baker, 1912), Crozet Island (T. crozettensis Soyer, Thiriot-Quievreux & Colomines, 1987), the Mediterranean Sea (T. fulvus Fischer, 1860), Japan (Bonin Islands T. igai Itô, 1977); Shimoda, (T. japonicus Mori, 1938), Kerguelen Island (T. kerguelensis Soyer, Thiriot-Quievreux & Colomines, 1987), Antarctica (T. kingsejongensis Park, S. Lee, Cho, Yoon, Y. Lee & W. Lee, 2014), Senegal (T. minutus Bozic, 1960), New Zealand (T. raki Bradford, 1967), and Thailand (Rayong, T. sirindhornae Chullasorn, Dahms & Klangsin, 2013; Bangsaen, T. thailandensis Chullasorn, Ivanenko, Dahms, Kangtia & Yang, 2012).
Identification of Iranian species based on
During an investigation on the intertidal copepod fauna of the Persian Gulf and the Oman Sea, a new member of the genus Tigriopus was discovered. Herein, we describe a new species of Tigriopus, T. iranicus sp. nov., which was found in rock pools in the Persian Gulf and the Oman Sea.
The description of some characters of T. raki were omitted in the original description, and a complementary redescription of the species is provided herein.
The studied material was collected from rock pools in the Persian Gulf and the Oman Sea during a short-term research project in 2016 on the harpacticoid fauna of Iran. Collected specimens were preserved in 96% ethanol for future investigation. One male and one female were stained in a 1:1 solution of Congo Red and Acid Fuchsin for 24 h (
Whole male and female specimens were used for the illustration of the dorsal and lateral views of the habitus. The material was then dissected using a Leica MZ12 stereomicroscope for a detailed description of mouth parts and appendages. Dissected appendages were mounted on permanent slides with glycerin as mounting medium and sealed with a mixture of honeybee wax and paraffin. Pencil drawings of dissected parts were prepared with a Leica DMR differential interference contrast microscope equipped with a drawing tube at a magnification of 1000×. Digital inking was done using Adobe Illustrator CS6. The type material was deposited in the collection of the Senckenberg Gesellschaft für Naturforschung (Frankfurt/Main, Germany). The descriptive terminology follows
Family Harpacticidae Dana, 1846
Genus Tigriopus Norman, 1869
Holotype: one adult female (SMF 37258/1-13) dissected, mounted on 13 slides. Allotype: one male (SMF 37259/1-11) dissected, mounted on 11 slides, and 115 paratypes (65 females and 50 males) preserved in alcohol (SMF 37260).
Rock tidal pool on the coast of Iran, Jask, Vanak, 25°32'5"N, 58°52'12"E.
With marked distinction between prosome and urosome. P1-bearing somite fused to cephalothorax. Female antennule nine-segmented; seven-segmented and chirocerate in male. Mandible with two naked setae on basis, palp with two-segmented endopod and exopod. Maxilla with two endites, each with two setae. P1 enp-3 with one claw, one spine, and one naked seta. P1 exp-3 with five well-developed claws. Endopodal lobe of female P5 with four pinnate setae. Female P6 with two setae. Inner seta of the male P2 enp-2 incorporated to the segment creating curved, pinnate process. Male P5 baseoendopods fused, forming a continuous plate, endopodal lobe without armature, exp with four elements.
Female. Total body length 630 µm, measured from tip of rostrum to posterior margin of furcal rami. Prosome four-segmented (Figs
Furcal rami
(Figs
Antennule
(Fig.
Antenna
(Fig.
Labrum
(Fig.
Mandible
(Fig.
Maxillule
(Fig.
Maxilla
(Fig.
Maxilliped
(Fig.
Swimming legs P1–P4
(Figs
Coxa | Basis | Exopod | Endopod | |
---|---|---|---|---|
Leg 1 | 0–0 | I–I | I–0; I–1; V | 0–1, 0–0; II+1 |
Leg 2 | 0–0 | I–0 | I–1; I–1; III, II,2 | 0–1; 0–1; I,2,1 |
Leg 3 | 0–0 | 1–0 | I–1; I–1; III, II,2 | 0–1; 0–1; I,2,1 |
Leg 4 | 0–0 | 1–0 | I–1; I–1; III, II,3 | 0–1; 0–0; I,2,1 |
P1
(Fig.
P2
(Fig.
P3
(Fig.
P4
(Fig.
P5
(Fig.
P6
(Fig.
Genital field
(Fig.
Male (Fig.
Antennule
(Fig.
P2
(Fig.
P5
(Fig.
P6
(Fig.
The specific epithet iranicus refers to the country where the new species was found. It is in the nominative singular. Gender masculine.
One female (SMF 37261/1-13) and one male (SMF 37262/1-10) paratype (
Leigh, north of Auckland, at about 36°30'S, 174°45'E on the east coast. Habitat: marine, in splash zone pool.
Female. Total body length 560 µm, measured from tip of rostrum to posterior margin of furcal rami. Few sensilla scattered on body surface (Fig.
Prosome
(Figs
Urosome
(Figs
Furcal rami
(Fig.
Antennule
(Fig.
Antenna
(Fig.
Mandible
(Fig.
Maxillule
(Fig.
Maxilla
(Fig.
Maxilliped
(Fig.
Swimming legs 1–4
(Figs
Coxa | Basis | Exopod | Endopod | |
Leg 1 | 0–0 | 1–1 | I–0; I–1; V | 0–1, 0–0; II+1 |
Leg 2 | 0–0 | 1–0 | I–1; I–1; III, II, 2 | 0–1; 0–1; I,2,1 |
Leg 3 | 0–0 | 1–0 | I–1; I–1; III, II, 2 | 0–1; 0–1; I,2,1 |
Leg 4 | 0–0 | 1–0 | I–1; I–1; III, II, 3 | 0–1; 0–0; I,2,1 |
P1
(Fig.
P2
(Fig.
P3
(Fig.
P4 (16B). Praecoxa triangular and unornamented. Coxa and basis largely as in P3. Enp-1 with one large pinnate inner seta; enp-2 unarmed; enp-3 with three pinnate setae and one pinnate spine. Exp-1 and -2 each with one outer pinnate spine and one inner pinnate seta; exp-3 with three pinnate outer spines, one outer and inner distal element ornamented as shown, and three pinnate setae.
P5
(Fig.
P6
(Fig.
Genital field
(Fig.
Male (Fig.
Antennule
(Fig.
P2
(Fig.
P5
(Fig.
P6
(Fig.
1 | Male antenna with abexopodal seta | 2 |
– | Male antenna without abexopodal seta | 3 |
2 | Male P2 enp-2 with well-developed knob | T. kingsejongensis |
– | Male P2 enp-2 without knob | T. kerguelensis |
3 | Female P5 enopod with five setae | 4 |
– | Female P5 enopod with four setae | 11 |
4 | Male P5 exopod with five setae | 5 |
– | Male P5 exopod with four setae | 7 |
5 | P4 exp-3 with seven setae/spines | 6 |
– | P4 exp-3 with eight setae/spines | 10 |
6 | P1 exp-3 with four claws and one pinnate seta | T. japonicus |
– | P1 exp-3 with five claws | T. californicus |
7 | Mandibular basis with one seta; female with two copulatory apertures | 8 |
– | Mandibular basis with two setae; female with one copulatory aperture | 9 |
8 | Male antennule eight-segmented; coxal endite of the maxillula with three setae; endopod of the maxilla with four setae | T. thailandensis |
– | Male antennule seven-segmented; coxal endite of the maxillula with five setae; endopod of the maxilla with two setae | T. sirindhornae |
9 | Mandibular endopod with eight setae | T. crozettensis |
– | Mandibular endopod with seven setae | T. angulatus |
10 | P1 enp-3 with one claw and two setae | T. brevicornis |
– | P1 enp-3 with two claws | T. fulvus |
11 | Maxillary syncoxa with three endites | 12 |
– | Maxillary syncoxa with two endites | T. iranicus sp. nov. |
12 | Antennary exp-1 with two setae | 13 |
– | Antennary exp-1 with one seta | T. brachydactylus |
13 | Male P5 baseoendopod without seta | 14 |
– | Male P5 baseoendopod with one seta | T. minutus |
14 | Maxillary endopod with four setae; mandibular basis with two setae | T. igai |
– | Maxillary endopod with three setae; mandibular basis with one seta | T. raki |
The new species, T. iranicus sp. nov., was allocated into Tigriopus on account of the combination of: 1) a nine-segmented antennule in the female; 2) a three-segmented antennary exopod (with setal formula 2.1.2); 3) a three-segmented P1 endopod; 4) male P2 enp-2 with outer apophysis; 5) P3 without sexual dimorphism, and 7) male P5 endopodal lobe reduced or absent.
Tigriopus iranicus sp. nov. is the third species of the genus reported from the Indian Ocean. Tigriopus crozettensis and T. kerguelensis were reported by
The great similarities between females of different species make subtle details necessary for separation of species (
In addition to differences with other congeners, T. iranicus sp. nov., displays a unique two-segmented mandibular endopod. Within the genus Tigriopus the mandibular endopod is one-segmented. The two-segmented condition in the new species indicates a plesiomorphic state in the genus. In comparison with other species, the P1 enp-3 armature of T. iranicus sp. nov. has a different armature. The P1 enp-3 has one developed pinnate claw, one strong geniculate spine, and one slender seta, which are undescribed and not shown in any other species of the genus.
The new species, T. brevicornis and T. minutus (see
As most older descriptions of species are incomplete, it is difficult to make further comparisons. Nevertheless, based on available information, the new species is most closely related to T. igai and T. raki, and seems to be more closely related to the latter. In addition to the apomorphies of T. iranicus sp. nov., there are several significant differences that separate the new species from the other two species. The new species differs from T. igai in: i) the number of setae on the female P6; ii) the number of endopodal and exopodal segments of the mandible; iii) the number of setae on the exopod of the mandible; iv) the number of setae on the coxal endite of the maxillule; and v) the number of setae on the syncoxal endites of the maxilla. Tigriopus iranicus sp. nov. differs from T. raki in the presence of: i) two setae on the mandibular basis (one in T. raki); ii) six setae on the basis of the maxillule (five in T. raki); ii) four setae on the exopod of the maxillule (three in T. raki); iv) two setae on the proximal syncoxal endite of the maxilla (four in T. raki); and v) three setae on the allobasis of the maxilla (two in T. raki).
Tigriopus raki was originally described from splash-zone pools from Northland, New Zealand by
The number of species currently attributed to Tigriopus increases to 15. Following
We thank Dr Samuel Gómez for helpful comments and useful suggestions on the manuscript. The first author is also grateful Dr Gritta Veit-Köhler for their helpful support during this work. We also thank Dr Janet Bradford-Grieve, c/o
Geographic coordinates
Data type: occurrence