Batillipes kalami Vishnudattan, Rubal & Bijoy Nandan, 2023

Vishnudattan, N. K., Rubal, Marcos & Nandan, S. Bijoy, 2023, A new species of Batillipes (Arthrotardigrada: Batillipedidae) from the mid littoral zone of the southeast coast of India, Zootaxa 5346 (2), pp. 163-172 : 165-169

publication ID	https://doi.org/ 10.11646/zootaxa.5346.2.4
publication LSID	lsid:zoobank.org:pub:5C8322AF-F2F8-48A3-8684-93971F78D817
DOI	https://doi.org/10.5281/zenodo.8368440
persistent identifier	https://treatment.plazi.org/id/0395D56B-F67F-FFCF-858B-FDDBFD641DBF
treatment provided by	Plazi
scientific name	Batillipes kalami Vishnudattan, Rubal & Bijoy Nandan
status	sp. nov.

Treatment

Batillipes kalami Vishnudattan, Rubal & Bijoy Nandan sp. nov.

( Figs. 2–5 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 , Table 1 View TABLE 1 )

Diagnosis. Medium sized Batillipes with cephalic region comprising a pair of tubular unconstricted-smooth primary clavae and indistinct secondary clavae. Cephalic cirri with sharp distal tips. External cirri are separated from the cirrophore of the primary clavae and lateral cirri by an indentation. Head is distinct and separated from the body by a neck constriction followed by a semi-circular lateral body projection. Sensory spines found on all legs. Leg IV sensory organ is short and finger like with van der Land’s organ at the mid region and a slightly swollen terminal portion. Single pair of lateral body projection between leg I–II, while two pairs of lateral body projection found between leg II and III. Lateral body projection between leg III and IV is longer and blunt ended. Body cuticle including lateral processes are finely punctated. Female gonopore is rosette-like while it is circular in males. Medium sized, terminally sharpened caudal spike attached on a cup shaped caudal base. Toes 3 and 4 of leg IV are shortest and are equal in length.

Materials examined. Holotype: MB /SBN/VD9: adult female mounted in glycerol.

Paratypes: MB /SBN/VD10-11, VD13, VD15, and VD18: five adult females mounted in glycerol ; MB /SBN/ VD12, VD14, VD16-17: four adult males mounted in glycerol .

Type locality: Mini Coral Beach, Mandapam, Maraikayar Pattinam, TamilNadu, southeast coast of India (9°16’18.54”N, 79°7’53.1”E) GoogleMaps .

Type depositories: Ten specimens containing slides mounted in glycerol were submitted in the Marine Biology Museum (voucher no: MB /SBN/VD9-18), of the Department of Marine Biology , Microbiology and Biochemistry, Cochin University of Science and Technology ( CUSAT), Fine Arts Avenue, Cochin-682016, Kerala, India

Description of holotype. Adult female with a body length of 170.2 μm (from the anterior rim of cephalic region to the posterior end of body excluding caudal spike) and a width of 51.5 μm between third and fourth leg ( Figs. 2 View FIGURE 2 , 3 View FIGURE 3 ; Table 1 View TABLE 1 ). Body width slightly increasing from cephalic to caudal region. Translucent body cuticle with fine punctations. Punctation is more evident in the ventral cuticle. Head is trapezoid in shape with a width of 45.4 μm bearing a set of cephalic appendages and separated from the body by a neck constriction. All the cephalic cirri are sharp tipped at the terminal portion. Internal cirri of 12.7 μm length bearing cirrophores (2.3 μm) are attached dorsally on the anterior rim of cephalic region ( Fig. 5A View FIGURE 5 ). Unpaired median cirrus (9.8 μm) attached to cirrophore (2.6 μm) is 4 μm distant from the anterior rim of mid cephalic region ( Fig. 4A View FIGURE 4 ). External cirri with indistinct cirrophores is 12.1 μm long ( Fig. 4A View FIGURE 4 ). Primary clava (11.7 μm) is smooth and unconstricted tubular structure with a blunt end ( Fig. 4A View FIGURE 4 ). Lateral cirri, 29.3 μm long is found very proximal to primary clava which arise from the common pedestal ( Fig. 5A View FIGURE 5 ). Van der Land’s organ is present at the base of each primary clava ( Fig. 4A View FIGURE 4 ). External cephalic cirri are separated from the cirrophore of the primary clavae and lateral cirri by an indentation ( Fig. 5A View FIGURE 5 ). Secondary clava is indistinct. Eye spots not visible. Ventral conical shaped mouth is 15.4 μm wide ( Fig. 5B View FIGURE 5 ). Circular pharyngeal bulb with 21.5 μm diameter is 15.4 μm posterior to the anterior rim of cephalic region. Buccal tube, stylet and placoids were not clearly visible after mounting slide in the holotype.

Five pairs of dorso-lateral body projections are present: a pair of semi-circular lateral projections, 9.9 μm long are found between the head and the first pair of legs. A blunt lateral body projection of 9.4 μm long are present between first and second leg pairs. Two pairs of blunt lateral projections are found between the second and third leg pairs. Among them first pair (11.5 μm) is attached more dorsally while the other pair (9.7 μm) is oriented a little more ventrally. Long blunt ended (18.4 μm), finely punctated-transparent lateral projections are present between third and fourth leg pairs. All lateral body projections are lined by finely punctated and thin transparent sheet at its margin ( Figs. 2 View FIGURE 2 , 3A View FIGURE 3 ).

All the pair of legs possess sensory spines of varying length (9.5–12.8 μm) with sharp tip at its distal end except for leg IV sensory organ. Leg IV sensory organ is a finger like structure terminated by a slightly swollen tip ( Fig. 4C View FIGURE 4 ), 11.7 μm long with a proximal portion and a distal portion separated by van der Land’s organ ( Fig. 4C View FIGURE 4 ). Sharply pointed and long Cirri E (22.5 μm) are attached dorsolaterally between caudal lateral body projection and leg IV ( Fig. 4D View FIGURE 4 ).

Telescopic legs with an average length of 27.8 μm and toes of varying length. Among the first three pair of legs, toe 2 and 4 are the shortest (6.1, 6 μm) and are of same length. Toe 1,3,6 (8.7–11.8 μm) are medium sized while the 5 th toe is the longest (17.1 μm). On the fourth pair of legs, toe 3 and 4 are almost sessile, of same length (5.6, 5.5 μm) and the shortest. Toe 1 (7.4 μm), toe 2 (11.9 μm) and toe 6 (7.3 μm) are longer than toes 3 and 4, while toe 5 (12.9 μm) is the longest ( Figs. 2 View FIGURE 2 , 3B View FIGURE 3 , 5C View FIGURE 5 ). The orientation of the toes of leg IV corresponds to the group A proposed by Santos et al (2018). Toes possess distally enlarged stalk with terminally attached ovoid and transparent suction discs (6.2 μm long x 5.2 μm wide on leg IV).

Rosette-shaped female gonopore with 6.1 μm width is present 6.6 μm anterior to the anus and 29.1 μm above the caudal base ( Fig. 5C View FIGURE 5 ). Caudal apparatus (22 μm long) consists of a cup shaped caudal base (10.1 μm long and 16.2 μm wide), where the base of caudal spike is attached. Caudal spike is 12 μm long with a sharp tip at its distal end lined by transparent sheet at its margin ( Figs. 2 View FIGURE 2 , 3A View FIGURE 3 ).

Remarks. No sexual dimorphism was found in this species, where both sexes are morphologically and metrically much similar, with an only exception of having a circular gonopore in males. Buccal tube, stylet and placoids were clearly visible in few of the paratypes ( Fig. 4B View FIGURE 4 ).

Etymology. The specific epithet, kalami refers to Dr. A. P. J. Abdul Kalam, Indian aerospace scientist and eleventh president of India also known as the “Missile Man of India ” who was native to the type locality of the current species.

Differential diagnosis. Batillipes kalami sp. nov. belongs to the group A species proposed by Santos et al (2018), based on the toe pattern on the feet of leg IV. This major group contains 26 described species ( Santos et al. 2018). However, only five species within this group have toes 3 and 4 sessile like B. kalami sp. nov. (i.e. B. crassipes , B. gilmatini , B. pennaki and two undescribed similar species to B. pennaki reported by Santos et al (2019b)).

Batillipes crassipes can be easily distinguished from B. kalami sp. nov. by the absence of lateral projections between legs III and IV, different shape and size of sensory organ on leg IV along with very short caudal spike ( Tchesunov & Mokievsky, 1995) while B. kalami sp. nov. have distinct lateral projections between leg III and leg IV and the leg IV sensory organ is a finger like structure terminated by slightly swollen tip and the caudal spike is consistently conspicuous in all the examined individuals.

Batillipes gilmartini can be differentiated from B. kalami sp. nov. by the presence of a constriction in the primary clavae and incomplete dorsal plates that are absent in B. kalami ( McGinty, 1969) . The description of B. gilmartini is very incomplete and does not provide details about some characters, but the drawing of B. gilmartini shows a single small lateral projection between legs III and IV while B. kalami sp. nov. shows conspicuous lateral projections between all pairs of legs.

Finally, B. kalami sp. nov. can be separated from B. pennaki ( Marcus, 1946) and the two similar undescribed species by Santos et al (2019b) by the lack of any constriction in the primary clavae in B. kalami . Moreover, the shape of the sensory organ on leg IV in B. kalami sp. nov. is similar to the undescribed species from European Atlantic shores but, it is different from B. pennaki and the similar Mediterranean species that both have a conicalshaped distal portion terminated by a lance-like tip ( Santos et al. 2019b). Finally, B. pennaki and the two undescribed similar species have a conspicuous lateral projection between legs III and IV. The lateral projection between legs III and IV in B. kalami sp. nov. is smaller and more pointed than the one of B. pennaki . Moreover, in B. kalami , lateral projections are present between all pairs of legs.