THE STEINHART AQUARIUM - Gulf of Guinea Science ...

78 A Docent Field Guide to the Species of the Steinhart Aquarium
oval body, about 9 cm long and 4 cm wide.
Females are slightly larger than males. They
commonly run along the ground, although
the adults have wings that are rarely if ever
used for flight. They have long, very slender
antennae and two sensory organs, called cerci,
at the tip of the abdomen.
Diet: Cockroaches are omnivores and detritivores.
They help recycle decaying matter on the ground
into useful nutrients for plants.
Reproduction and Development: All species
of cockroaches are ovoviviparous. After
mating, the female forms a protective pouch
to hold the eggs until they hatch. She keeps
the pouch inside her abdomen, taking it out
only once to turn it and retracting it until
gestation is complete. Incubation is about 60
days. The female expels the pouch when the
eggs start to hatch.
Mortality/Longevity: They can live about 20
months as adults.
Remarks: Females emit a pheromone that
induces males to mate. Male courtship rituals
include raising wings at right angles to
abdomen and making trembling movements
with abdomen.
Happily these huge insects provide services to the
forest, and are not found in the average kitchen!
Madagascar Hissing Cockroach
Gromphadorhina portentosa (Blaberidae)
Distribution: Madagascar.
Habitat: Tropical lowland forest floor, hiding
in leaf litter and rotting logs.
Appearance: Dark brown exoskeleton, no
wings, foot pads and hooks to climb smooth
surfaces. Females have larger, heavier bodies.
Males sport horns. They are one of the largest
cockroach species in the world (5–7.5 cm long
and weighing up to 25 gm).
Diet: Nocturnal scavengers of decaying plant
material, small insects and animal carcasses.
Reproduction and Development: Mating
occurs year around. The male hisses during
courtship by constricting its abdomen to
expel air through breathing holes (spiracles),
producing both calling and courtship sounds.
Females carry 15–40 eggs internally, then bear
live young. Nymphs molt their exoskeleton
as they grow, reaching sexual maturity in
7 months. Parents and offspring stay close
for extended periods. Males defend mating
territories, and use their horns in fights with
rivals, ramming each other and hissing loudly.
Mortality/Longevity: Likely predators include
large spiders, tenrecs, and birds. When
disturbed, both sexes sound an alarm hiss
to startle predators. Can live up to 5 years.
Conservation Status: These cockroaches live
in forest pockets that are dying (degradation
and fragmentation) so Madagascar is a top
conservation priority.
Remarks: Territory sizes are small: a male
may sit on a rock and defend it for months.
Dominant males stand on their “toes” to “show
off.”
Indigenous people call this species Kofokofoka,
approximating the hisser’s call.
Madagascar hissing cockroaches are not pests,
do not inhabit houses, cannot fly, are not
aggressive, and do not bite.
ORDER MANTODEA
(PRAYING MANTIDS)
Ghost Praying Mantis
Phyllocrania paradoxa (Hymenopodidae)
Distribution: Tropical Africa including
Madagascar, Mozambique, Namibia, Somalia.
Habitat: Warm, highly humid tropical forests.
Appearance: Miniature species of leaf mantis,
growing to under 5 cm. Sexual dimorphism is
usual, with females slightly longer, and having
a wider abdomen than males. Colors can vary
from grey/green to dark brown or almost
black. Colors are dependent on humidity and
light levels. Phyllocrania has leaf-like head and
shoulder shields, and leaf-like protrusions
hanging from its limbs. This “dead-leaf”
appearance makes it very difficult to see.
Diet: In captivity ghost mantids eat Drosophila,
houseflies, crickets, flour worms.
Reproduction and Development: No specific
information found. In general mantids
reproductive organs are found at the tip of
their abdomen. Females usually attract males
with pheromones, there is a brief courtship
dance, and the male alights on the female’s
back. After fertilization the female deposits
batches of eggs, using an ovipositor at the tip
of her abdomen. The eggs stick to stems and