Pelvimetry in Squirrel Monkeys (Saimiri scireus Linnaeus, 1758)

Abstract

Saimiri sciureus is a neotropical primate widely used in research. However, there are still difficulties regarding their reproduction in vivaria due to the high incidence of dystocia. Dystocia in primates can be caused by cephalopelvic disproportion and in Squirrel Monkeys, pregnancy of large fetuses were reported. This paper describes pelvimetry data of adult females and subadults in specimens of Squirrel Monkeys, from a research colony of Para, Brazil. Pelvic radiographs were obtained in ventrodorsal projections and the following measurements were taken: superior bi-iliac diameter (SBID); inferior bi-iliac diameter (IBID); bi-iliac average diameter (BIAD); right diagonal diameter (RDD); left diagonal diameter (LDD); sacro-pubic diameter (SPD); Based on the obtained diameters, the entrance area of the pelvis (EAP) was also calculated. The average values of the pelvic diameters and EAP in adult females were SBID 1.714cm, BIAD 1.957cm, IBID 1.686cm, RDD 2.771cm, LDD 2.764cm, SPD 2.543cm and EAP 3.9056cm2; and subadult females: 1.588cm SBID, 1.850cm BIAD, 1.625cm IBID, 2.50cm RDD, LDD 2.474cm, 1.95cm SPD and 2.8293 cm2 EAP. Saimiri sciureus pelvis is characterized as dolichopelvic. There was statistical significance between the values for adult females and subadults to SBID, BIAD, RDD, LDD, SPD and EAP. The values of SBID and IBID were lower when compared to the published data for the same species. The result found on this paper will serve as a basis for future studies using pelvic measurements and dystocia prediction of neotropical primates and comparison between different vivaria.

Radiographic measurements of the hind limbs in capuchin monkeys (Sapajus spp.)

“…in the present study was statistically higher for adult females compared to adult males and sub‐adult females. These data are in agreement with previous studies that observed a larger pelvic inlet in females than in males in adult Callithrix jacchus , 8 and a lower superior bi‐iliac diameter and smaller pelvic inlet in sub‐adult females in Saimiri scireus compared to adult females 9 . In the current study, except for the right diagonal diameter, all pelvimetry measurements in sub‐adult females were statistically similar to those of males.…”

Radiographic pelvimetry in the Tamandua tetradactyla

“…These measurements were performed according to protocols established by MONTEIRO et al (2012), PINHEIRO et al (2016), andFAVORETTO et al (2018), under the following conditions: upper bi-iliac diameter (AB), drawing a straight line across the longitudinal diameter of the pelvis at the smallest diameter of the sacroiliac joint; lower bi-iliac diameter (CD), drawing a straight line parallel to the AB diameter, which was measured at the ilio-pubic junction. We also measured two diameters diagonally: the right diameter, which went from point A to D; the left diameter, which started at point B and went on to C, at the intersection point of the diagonal diameters, parallel to the upper bi-iliac and lower bi-iliac diameters, and a third transverse diameter was drawn, that is, the middle bi-iliac (EF), which went from the medial face of the right ilium to the left ilium (Figure 1).…”

Radiographic study of the axial and appendicular skeleton of Callithrix jacchus and Callithrix penicillata

“…Pelvimetry diameter values were obtained including the upper bi‐iliac, lower bi‐iliac, mid bi‐iliac, right diagonal, left diagonal, and sacro‐pubic. From these values, it was possible to calculate the pelvic entry area using the following formula: (mid bi‐iliac diameter/2) × (sacro‐pubic diameter/2) × π. Measurements were performed according to previous descriptions in primates 9,11,22,23,24 . The measurement points on the radiographic images in ventrodorsal projection are shown in Figure 1A.…”