taxonID	type	description	language	source
9851EEA4949C5DAF936508704BAE1098.taxon	description	Figs 2, 3, 4, Tables 1, 2	en	Zhou, Zhiqian, Lian, Xiping, Tan, Yehui (2025): A new species of Monstrilla (Copepoda, Monstrilloida) in coastal waters of northern South China Sea. ZooKeys 1232: 237-248, DOI: 10.3897/zookeys.1232.144830
9851EEA4949C5DAF936508704BAE1098.taxon	etymology	Etymology. The species name is derived from the Greek word pseudo, meaning “ false ”, and the name of the closely similar M. grandis Giesbrecht, 1891.	en	Zhou, Zhiqian, Lian, Xiping, Tan, Yehui (2025): A new species of Monstrilla (Copepoda, Monstrilloida) in coastal waters of northern South China Sea. ZooKeys 1232: 237-248, DOI: 10.3897/zookeys.1232.144830
9851EEA4949C5DAF936508704BAE1098.taxon	diagnosis	Diagnosis. Female Monstrilla with smooth cuticle on cephalothorax; forehead medially concave, bearing a pair of short sensilla and small setae bilaterally near antennule bases. Cephalothorax ventrally marked by four pairs of small, nipple-like scars, arranged symmetrically anterior to oral papilla. Oral papilla located at approximately midlength of cephalothorax, ventrally posteriorly-bent. Antennule two-segmented, segments fused distally, reaching 37.8 % of total body length. Legs 1 – 4 with relatively short outer exopodal spines. Fifth legs bilobed, outer lobe elongate, with three plumose setae; inner lobe shorter, bearing two plumose setae and a basal protuberance on inner margin. Caudal rami 2.1 times as long as wide, divergent posteriorly, each armed with six well-developed caudal setae.	en	Zhou, Zhiqian, Lian, Xiping, Tan, Yehui (2025): A new species of Monstrilla (Copepoda, Monstrilloida) in coastal waters of northern South China Sea. ZooKeys 1232: 237-248, DOI: 10.3897/zookeys.1232.144830
9851EEA4949C5DAF936508704BAE1098.taxon	description	Description of adult female holotype. Body moderately elongate (Fig. 2 A – C), about 1.68 mm, measured from anterior end of cephalothorax to posterior margin of caudal rami, excluding antennules and caudal setae. Cephalothorax rather large and relatively long, accounting for about 57.7 % of total body length, transparent, dorsal surface smooth; anterior 2 / 5 slightly swollen laterally and ventrally. Nauplius eye present, weakly developed, elliptical, ocelli unpigmented with separate oval hyaline bodies, separated by 1 ½ eye diameter (Fig. 2 A). Anteriormost part of cephalothorax with ventral, rounded convex protuberance with irregular margin in lateral view (Fig. 2 B); cuticular ornamentation observed on the surface of cephalothorax in lateral and ventral view. Forehead slightly concave medially between antennulary bases in dorsal view, without rostral protrusion, bearing a pair of short, slender sensilla in the middle and a pair of setae near first antennule (Fig. 3 B at arrow); weak, fine, longitudinal and transverse wrinkles running behind antennular bases on each side of lateroventral surfaces, flanked by four pairs of small nipple-like scars ahead of oral papilla (Fig. 3 A at arrow), without sensory pore. Oral papilla situated slightly posterior to midlength of cephalothorax, accounting for about 52.9 %, protruding ventrally, with distal half posteriorly-bent (Fig. 3 A). Antennule long (Fig. 4 A, B), about 37.8 % of total body length, about 65.5 % of the cephalothorax; antennule two-segmented, only first segment distinctly separate, remaining segments fused, with constrictions along antennular body representing places of intersegmental divisions (purported 2 – 5), length ratio of antennule segments, from basal to distal one: 14.0: 86.0 (= 100). In terms of the pattern described by Grygier and Ohtsuka (1995) for female monstrilloid antennulary armature, setae (Roman numerals) and spines (Arabic numerals), short, slender element 1 present on first segment; purported segment two with elements 2 d 1, 2 d 2, 2 v 1, 2 v 2, 2 v 3, IId; purported segment three with elements 3, IIId and IIIv; purported segment four with elements 4 v 1 – 2, 4 d 1, IVd and IVv as well as 4 aes (aesthetasc); purported segment five with elements 5, Vd, Vv and Vm; setae b 1 – 3, b 5 all dichotomously branched from proximal half or third, setae b 4 simple, without b 6. Apical elements 6 1, 6 2, and 6 aes present, but 6 aes absent on right antennule in dorsal view. Legs 1 – 4 (Fig. 3 D – G) all with both endopod and exopod three-segmented. Coxa without setae and lacking marginal rows of setae or spines. Basis not fully divided medially from coxa; all outer basal setae on legs 1 – 4 slender, naked; seta on leg 3 much longer. First and second exopodal segments of legs 1 – 4 slightly swollen, third exopodal segement undulate along outer distal margin; outer margins of all endopodal segments swollen and smooth. Outer distal spines on first and third exopodal segments of legs 1 – 4 feeble, much shorter than segments bearing them. Seta / spine armature of swimming legs 1 – 4 as in Table 1. Leg 5 bilobed, both lobes confluent basally and divided distally. Outer lobe elongate, armed with three long, plumose setae apically or subapically, of subequal lengths. Inner lobe relatively short, with a basal protuberance on inner margin (arrowed in Fig. 3 C), its tip exceeding the half of the outer lobe, armed with two plumose setae apically or subapically. Urosome consisting of four urosomites: fifth pedigerous somite, genital double-somite, free postgenital somite and anal somite, accounting for 17.9 % of total body length, excluding caudal setae; ratio of lengths 30.3: 44.0: 15.4: 10.3 (= 100). Genital double-somite representing almost half-length of urosome (44.0 %), somewhat swollen laterally, partial suture visible; about 1.7 times longer than the combined length of the next two segments. Genital double-somite bearing pair of long ovigerous spines, these being inserted on middle of ventral surface, basally separated, with pointed tips extending far beyond tips of caudal setae, in total equal to about 38.2 % of total body length. Anal somite trapezoidal; lateral margin nearly smooth in dorsal but with apparent notch in ventral; lacking wrinkles or striae both on dorsal and ventral surfaces. Caudal rami long (Fig. 3 C), about 2.1 times as long as wide; divergent outward; with small cuticular protuberance at basal part of outer face and slightly swollen at distal part of inner face; each ramus armed with six well-developed caudal setae, consisting of two distal, two lateral, one inner distal, and one dorsomedial setae.	en	Zhou, Zhiqian, Lian, Xiping, Tan, Yehui (2025): A new species of Monstrilla (Copepoda, Monstrilloida) in coastal waters of northern South China Sea. ZooKeys 1232: 237-248, DOI: 10.3897/zookeys.1232.144830
