Endeis meridionalis
Creators: name: George, Zarish
name: Siddiqui, Ghazala
name: George, Nazish
name: Lucena, Rudá Amorim
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Pycnogonida
Endeididae
Endeis
Endeis meridionalis

description: Endeis cf. meridionalis (Böhm, 1879)
(Figure 9)
Phoxichilus meridionalis Böhm, 1879: 189–191, pl. 2, fig. 4.
Material examined: (CEMB, PYC– 026), 1♀, Sandspit, 26.iii.2014, on Zoanthus sansibaricus.
Description: Trunk length 1.7 mm, slender, completely segmented. Lateral processes elongated, separated by twice their diameter and with two dorsal tubercles. Ocular tubercle high, bell-shaped. Proboscis cylindrical, elongated with many short setae at distal end. Abdomen short, oblong, rounded distally, with many setae, hardly reaching the distal margin of the fourth lateral process. Legs long, slender; coxa 2 larger than coxa 1 and coxa 3; femur and tibia 1 with distal spine; femur and tibia 2 subequal, tibia 1 shorter than the others; tarsus small, with few ventral setae, propodus with six to seven distal setae, heel slightly prominent, with four spines, sole straight, with five or six spines; main claw curved, less than half of the propodus length; auxiliary claw two-thirds of the main claw.
Measurements (mm): Length of trunk (measured from the anterior margin of the cephalic segment to distal margin of the lateral process 4), 1.75; trunk width (across segment 2), 0.75; length of abdomen, 0.2; length of proboscis, 01; third leg – coxa 1, 0.25; coxa 2, 0.5; coxa 3, 0.25; femur, 1.25; tibia 1, 01; tibia 2, 1.27; tarsus, 0.1; propodus, 0.45; main claw, 0.175; auxiliary claws, 0.075.
Remarks: Identification of a single female in this genus is difficult. Two species are known in Pakistan, E. mollis (Carpenter, 1904) and E. meridionalis (Böhm, 1879). Both were reported from Clifton (Gul & Ghani 2012), while E. biseriata Stock, 1968 was reported from the Gulf of Oman (Lucena et al. 2018).
This specimen is most closely related to E. meridionalis due to the presence of four heel spines, spines on the dorsal margin of coxa 1 of all legs, a slightly longer tibia 2 than the femur, and the distance between the lateral processes (twice own diameter). The kinked femora were not observed however, which is a well-marked feature of E. meridionalis (Clark 1973), besides the presence of two spines on the dorsal surface of all lateral process and coxa 1 (E. meridionalis has been described as having two spines in the lateral process 1, and one spine in the others). When we compare the present specimen with the other species registered for the region, they can be distinguished by the absence of spines on the lateral process in E. mollis, and the presence of a long distal spur on the femur and three heel spines in E. biseriata.
The present species also shares similarities with E. spinosa (Montagu, 1808) and E. charybdeae (Dohrn, 1881), but E. spinosa differs by having three heel spines on the propodus, a longer proboscis (more than half of the body length), no lateral spines on the femur, and two spines on the first lateral process and one in all the others (Child 1992). Endeis charybdeae has a slender habitus, five heel spines (Koçak & Katangan 2008), just one spine on the lateral process, coxae and tibia much longer than the femur. Because of the difficulty in identifying species of this genus, the absence of a male, and the differences observed between our specimen and E. meridionalis, (the most closely related species), we prefer not to confirm the identification until more specimens are examined in the future.
Distribution: Indian Ocean (Calman 1923), Southwestern Indian Ocean, Gulf of Suez (Böhm 1879), Somalia (Stock 1982), Kenya (Arnaud 1973), Madagascar (Stock 1965), Japan (Utinomi 1971), Papua New Guinea (Clark 1973), Indo pacific (Müller 1990b), Ross Sea (Fry & Hedgpeth 1969), Atlantic to Mediterranean (Soler-Membrives & Munilla 2015).
description: Published as part of George, Zarish, Siddiqui, Ghazala, George, Nazish & Lucena, Rudá Amorim, 2020, A new species of Achelia (Pycnogonida: Ammotheidae) and first records of intertidal sea spiders found on Zoanthus (Cnidaria: Zoantharia) from Karachi Pakistan, pp. 371-393 in Zootaxa 4821 (2) on page 384, DOI: 10.11646/zootaxa.4821.2.9, http://zenodo.org/record/4398801