Brasilibathynellocaris salvadorensis (Noodt, 1962)

Corgosinho, Paulo H. C., Arbizu, Pedro Martínez & Dos Santos-Silva, Edinaldo N., 2010, Revision of Brasilibathynellocaris Jakobi, 1972 (Copepoda: Harpacticoida: Parastenocarididae) with redefinition of the genus, Zoological Journal of the Linnean Society 159 (3), pp. 527-566 : 550-551

BRASILIBATHYNELLOCARIS SALVADORENSIS ‘FORMA LANCEOLATA’

Parastenocaris salvadorensis f. lanceolata – Noodt (1962: 235); Rouch (1986), Dussart & Defaye (1990).

Material examined: Noodt (1962) reported material from samples S 310 and S 311, which was collected from different spots at the same site; we found no material from S 310, thus observations were based on ten females from S 311.

Collecting locality: El Salvador, Laguna de Ilopango near San Salvador, groundwater from sandy beach at Balneario Apulo.

Diagnosis: Females of B. salvadorensis f. lanceolata differ from the nominotypical form only in the furca ( Noodt, 1962: 236, figs 40, 41).

Description of neotenic male of B. salvadorensis Neotenic male with five urosomites and telson. No distinct difference in shape and armature of furca. A2, legs 1 and 5 as in normally developed male. A1 ( Fig. 18A ) eight-segmented, as in male, but weakly geniculate; without the normal development of the fifth segment that can be seen in the male. Praecoxa of legs 2 and 4 is a distinct and relatively large triangular section adjacent to the outer proximal corner of coxa ( Fig. 18C, D ; not observed for leg 3). Leg 2 ( Fig. 18D ) as in male, but with a row of spinules on distal inner corner of exp-2 not transformed into hair-like spinules. Leg 3 ( Fig. 18B ) basis with a long outer seta, a strong curved spinule, and endopod represented by a seta; exopod two-segmented; exp-1 with a strong outer spine homologous to the thumb and an inner hyaline cushion; exp-2 with a distal spine; thumb and exp-2 spine with a hyaline border. Leg 4 ( Fig. 18C ) with three-segmented exopod; exp-1 not transformed as in normally developed male, with the proximal invagination on proximal inner corner, without an anterior row of strong spinules; in this case, the plesiomorphic condition is expressed in the neotenic male as a distal row of spinules on distal inner corner of the segment.

Description of copepodid V of B. salvadorensis

Male copepodid with four urosomites and telson. Furca with seven setae ( Fig. 19A ); seta II not extremely reduced. A1 seven-segmented ( Fig. 19B ), with aesthetascs present on segments 4 and 7. Praecoxa as a distinct and relatively large triangular section adjacent to the outer proximal corner of coxa of legs 3 and 4 ( Fig. 19C, D ). Leg 3 ( Fig. 19C ) with lamelliform endopod; exopod two-segmented, exp-1 without inner hyaline cushion and with a distal inner tube pore, exp-2 without distal hyaline frill; basis with a long outer seta and without strong curved proximal spinule; thumb and exp-2 spines without hyaline margins; structures that appear only in the adult, such as the exp-1 hyaline cushion and the basal hook-like spinule (indicated by dark arrows) can be seen inside the copepodid V limb. Leg 4 coxa without the two anterior modified spinules ( Fig. 19D ); endopod lamelliform, triangular, with a transverse row of spinules inserted at the midlength of the segment and without hyaline distal margin; exp-1 without invagination on proximal inner corner, rectangular and with distal hyaline frill on inner corner; the strong row of anterior spinules of exp-1, the two modified basal spinules and the outer serrated endopod margin that appear in the adult can be seen inside the copepodid V limb and are indicated by dark arrows. Leg 5 ( Fig. 19E ) with an inner process, an intercoxal plate, an outer basal seta, and three setae inserted on outer margin; proximal exopodal seta adjacent to outer basal seta very reduced.

Figures

Figure 18. Brasilibathynellocaris salvadorensis, neotenic male. A, antennule. B, leg 3. C, leg 4. D, leg 2. Scale bars (upper for A–C, lower for D) = 20 Mm.

Figure 19. Brasilibathynellocaris salvadorensis, male of copepodid V. A, furca. B, antennule. C, leg 3. D, leg 4. E, leg 5. Solid arrows point to structures of the adult developing inside the copepodid; open arrows point to structures of the copepodid that will be reduced or absent in the adult. Scale bars (upper for A–D, lower for E) = 20 Mm.