Two New Species of Chaetognatha from the Waters off Peru 
Paul N. Sund 1 
Since February, 1958, the Consejo de Investi- 
gaciones Hidrobiologicas of Peru has been mak- 
ing regular cruises to investigate the biological 
and hydrographic conditions off the coast of 
Peru. Through the kindness of Dr. Z. Popovici, 
I have been able to examine the Chaetognatha 
from plankton tows taken in the course of these 
investigations. The tows were made at the sur- 
1 Inter-American Tropical Tuna Commission, 
Scripps Institution of Oceanography, La Jolla, Califor- 
nia. Manuscript received April 29, I960. 
Sagitta peruviana n. sp. 
Fig. 2 A-L 
Holotype, 1 specimen, USNM no. 29921 
Paratypes, 10 specimens, USNM no. 29922 
Body rigid, opaque, hispid. Tail segment 23-29 per cent of total length. Anterior fins com- 
pletely rayed, start at posterior end of ventral ganglion. Posterior fins separate from anterior 
fins, completely rayed, reach posteriorly to seminal vesicles; greatest portion on tail segment, widest 
behind tail septum, about same length as anterior fins, posterolateral margin somewhat concave. 
Caudal fin triangular with rounded lateral apices; in contact with seminal vesicles. Anterior teeth 
4-9; posterior teeth 10-21; hooks 7-9. Seminal vesicles, when mature, with expanded anterolateral 
corner. Ovaries may extend to neck; ovaries with ova not filling body cavity, ova in two dorsoven- 
trally placed rows. Collarette conspicuous, extends posteriorly to approximately Vi distance between 
head and ventral ganglion. Corona ciliata extends from between eyes to about 2 A distance from head 
to ventral ganglion. Intestinal diverticula absent. Eye pigment dense, apparent shape quadrangular, 
with elongate extension arising medially from center of median side of pigmented area. 
BODY 
LENGTH 
IN MM. 
TAIL 
SEGMENT 
Vo TOTAL 
HOOKS 
ANTERIOR 
TEETH 
POSTERIOR 
TEETH 
MATURITY 
STAGE 
LENGTH 
OF OVARY 
IN MM. 
13.2 
24.0 
8 
9 
21 
IV 
7.1 
12.8 
24.2 
8 
9 
19-21 
II-III 
2.1 
11.9 
24.4 
7 
9 
15-18 
K?) 
1.1 
11.4 
24.5 
7 
— 
17-18 
Ill 
1.3 
11.3 
25.7 
8 
— 
— 
III-IV 
4.1 
10.9 
25.7 
8 
8 
20 
hi 
4.1 
10.5 
25.7 
7 
— 
— 
ii-iii 
1.2 
10.4 
24.0-25.0 
7-8- 
7-8 
16 
III-IV 
2. 5-2. 7 
10.1 
25.7 
8 
6 
19 
in 
2.9 
9.8 
23.0 
8 
6 
12 
III-IV 
3.0 
9.1 
24.2 
7 
5 
13 
III 
2.7 
8.4 
25.0 
8 
8 
15 
Juv. 
— 
7.2 
26.4 
8 
5 
13 
Juv. 
— 
6.8 
25.0 
8 
5 
12 
Juv. 
— 
5.8 
29.3 
9 
4-6 
10-11 
Juv. 
— 
5.3 
26.4 
8 
4 
10 
Juv. 
— 
face, using Vi -meter nets. 
The first specimens of the two new species 
reported were noted in a plankton sample taken 
on March 5, 1958, near the entrance to the Port 
of Talara, Peru. Inspection of other samples 
taken during the expedition (cruise 5802) re- 
vealed numerous individuals of one of the new 
species, Sagitta peruviana ; but none of the sec- 
ond species, Sagitta popovicii, was noted (Fig. 
1 ) . The descriptions of the new species are 
based on specimens preserved in formalin. 
105 
